Home Building Handbook
Table of Contents
FOREWORD
BUILDING GUIDE
Lot Preparation
Foundation
Framing
Roofing
Plumbing
Electrical
HVAC
Exterior finish
Insulation
Drywall
Finish Work
Drywall finishing
Exterior Trim
Interior trim
Painting
Plumbing
Electrical
Floor coverings
Final Inspection
CONSTRUCTION PHASES CHECKLIST
Lot Preparation
Foundation
Framing
Roofing
Plumbing
Electrical
HVAC
Exterior finish
Insulation
Finish Work
Drywall finishing
Exterior Trim
Interior trim
Painting
Plumbing
Electrical
Floor coverings
FOREWORD
BUILDING a home can be a very exciting and rewarding experience. But just like any large investment of money and time, homebuilding requires a good deal of planning, foresight, and maintenance. Whereas simply signing on the dotted line and turning over the reins of a project for someone else to handle may at first seem like an attractive strategy, experience has taught us that keeping a finger on the pulse of a project will result in a more fulfilling experience and help to avoid frustrating and costly mistakes and misunderstandings. Some degree of involvement is very beneficial.
(Please note: If you are planning to act as your own general contractor, please take note of the section addressed to Owner/Builders below.)
This handbook is designed to provide the homebuilder with an overview of the various phases of construction as well as some valuable tips and insights regarding each phase. Building contractors will often develop a Gantt chart for use with each project. This is a scheduling tool, in either printed or electronic format, which outlines the order and time projections for each phase. These charts are helpful for both the contractor and his customer. Using a Gantt chart, the builder will know when to schedule subcontractors and will be able to maintain deadlines and stay on track. In addition, it enables the customer to follow the progress of his project. Although the phasing outlined in this handbook follows what could be termed a typical custom home building project, some contractors may do things in a slightly different order and some projects may require additional or fewer phases. So, this is a general outline of standard practices and procedures in the custom home building industry.
In this regard, a word of caution is in order here. Whereas keeping a close eye on steps and phases in a home building project is desirable, a fine line can be drawn between being involved and micromanaging. Most contractors are happy to work with their customers throughout each of the phases, explaining the various aspects of the project as they go along. Indeed, a good deal of communication is often necessary because many details cannot always be included in the blueprints. When you choose your contractor, you should have a good feel, not only for his competence, but also for his willingness to communicate. However, it can be detrimental for a customer to question the contractor or his project manager about every detail and every perceived variation throughout the job. This can not only create an unhealthy relationship between the parties but it can also result in unnecessary delays. Please keep in mind that the steps outlined in this handbook are simply guidelines and not hard-and-fast rules. The ultimate success of a building project depends greatly on cooperation between parties.
SPECIAL NOTE TO OWNER/BUILDERS
If you intend to act as your own general contractor, you will obviously be a lot more involved in your project than if you hire a contractor. The degree of involvement depends on, among other things, your ability, experience, and business acumen. You may choose to manage some phases of the project but leave others to a contractor. For instance, you may wish to handle all of the basic structural work such as grading, foundation, framing, and roofing as well as the permits associated with each but leave the electrical, plumbing, siding, and interior/exterior finishing to someone else. You may also choose to do some of the actual physical work yourself. If you frame houses for a living, for example, you may choose to do all of the structural framing yourself but hire subcontractors to care for the balance of the project.
Whichever route you take, it is essential that everyone involved be on the same page. All contracts written between yourself, contractors, and subcontractors need to clearly specify the extent to which each of you will be involved, your rights and responsibilities, and the expectations of all parties.
A number of functions take place even before the shovel first hits the dirt. This handbook concerns itself only with the actual construction of the home. Therefore, it assumes that all of the preliminary work—which can be considerable—has already taken place. These tasks include acquiring the property, determining a budget, choosing an architect, designing the home, selecting a builder, and obtaining necessary permits. Utilities that are going to be used (electric, gas, and water, for example) are either already located on the property or have been brought to the property line by the utility companies and are available for connection during those phases of construction. It further assumes that all of the equipment (including portable toilets for the workers’ use), materials, and labor for the opening phase are in place, set up, and ready for groundbreaking!
Aside from the financial functions such as getting a loan, all of this preliminary work will be handled by the general contractor. However, if you are acting as your own contractor, the responsibility for virtually everything will rest upon you. The need for careful and extensive preplanning is necessary regardless of the contract situation that you choose, but as an owner/builder, it is absolutely essential. It has been said that as much time should be put in to planning for building the home as is put in to actually building it. In other words, if the estimated time for construction is six months, you will likely spend six months preparing for construction, making the entire project from property acquisition to certificate of occupancy about a year or longer. Those who choose to be an owner/builder and put the appropriate amount of time into the preliminary stages of construction nearly always enjoy an exciting and fulfilling journey toward home ownership.
The major phases in any custom homebuilding project, once all the preliminary work has been done are:
1. Lot Preparation
2. Foundation
3. Framing
4. Roofing
5. Plumbing
6. Electrical
7. HVAC
8. Drywall
9. Finish work
10. Final inspection
These are major divisions; there are numerous operations, large and small, that take place within each of these divisions. In addition, not all phases are mutually exclusive. Some may begin during one phase and be completed in another. Many overlap each other. For example, drywall finishing is typically included in the Finish Work phase even though it is an extension of the Drywall phase. Water and waste pipes and electrical wiring may be roughed-in during the Plumbing and Electrical phases but the plumbing and electrical fixtures are installed during the Finish Work phase. Most Gantt charts will reflect these overlaps, but not all. It depends entirely on the contractor/project manager. Again, appropriate communication between contractor and customer will minimize misunderstandings and promote good relations between parties. As mentioned before, the phasing outlined in this book follows a typical construction project.
If you have never built a house before, this handbook can be used like a school textbook on a course of construction theory rather than a shop class, since you will likely not be wielding a hammer personally. Such a difference might be compared to the difference between a school course on music appreciation rather than one on learning to play an instrument. In the other hand, if you will be doing some of the physical construction itself, this outline will enable you to see where your work will fall in the entire scheme of things. And if you are acting as your own contractor, you will undoubtedly be using the information contained herein both as a planning guide and as a working checklist. If you have built a home before, this can be considered a refresher course. So let this handbook help you enjoy an immersive experience in the construction trades while watching your dream home take shape.
Whatever the case, as a part of the essential planning stage, be sure to read through this book in its entirety before beginning your project and then refer to it regularly throughout the course of the build. Plenty of space has been provided for you to take notes as you go along. In addition to serving as a construction primer, it also represents a permanent record of your home building experience. You will find this book immensely helpful in making this experience a pleasant and enjoyable undertaking.
All the best,
—The Publishers
NO undisturbed land is ready-made for building a house. The site must go through a rigorous facelift in order to provide a safe and suitable base on which your home will rest. This is often referred to as “developing” the property. It usually will involve heavy equipment such as backhoes, bulldozers, graders, dump trucks, and sometimes even cranes. Trees and debris must be removed, the building pad leveled, and underground utilities installed. Here are some of the activities to expect once the lot prep work begins:
Staking the property
The surveyor will identify and mark property lines and establish legal setbacks. He will then “rough-stake” the building pad. This is one of the things that a homeowner can also do himself ahead of time if he would like the home to have a particular location or orientation that may not have been entirely specified in the architectural drawings. It basically involves driving wooden stakes at the four major corners of the pad site. The developer may fine-tune their location and ensure the squareness of the pad. This will be the reference that the graders and excavators will use in preparing the site.
Grading permit
Typically, after the property is staked, the contractor will apply for a grading permit which will allow him to clear and grade the property in preparation for construction. Often, during the same period of time, he will meet with a sediment control inspector to determine what kind of erosion control will be necessary for the project.
Erosion control
Often required by the governing municipality, erosion control is a method used to prevent rain and construction water runoff from carrying mud from your property to adjacent properties and the main road. Various methods of erosion control can be used, depending on the size of your property and whether there are any sensitive areas that need to be considered. The most common of these are hay bales, sand bags, silt fences, and fiber rolls. Silt fencing is a long roll (100’ to 1,500’) of fabric which will allow water to pass through but not dirt. There are wooden stakes attached to the fabric every 6’-10’. The silt fence is staked to the ground around the property where erosion could pose a problem. Fiber rolls are made of coconut fiber or straw and formed into long sausage-like tubular strands and are most often used for sloped sites. Similar material is used for making erosion-control blankets. At times, all that is needed are some well-placed sand or gravel bags or bales of hay. The hay can left in bales or broken open and spread over areas that may be prone to becoming muddy in order to stiffen the soil and slow down mud flow. The method(s) to be used are typically specified in the building plans.
After the erosion control measures have been taken, the contractor will call for an inspection. Once this has been signed off and the clearing permit has been issued, site work can proceed as planned.
Clearing
Most building sites will have trees, rocks, brush, and debris on it in places that will eventually be occupied by your new home, yard, outbuildings, etc. These are usually removed with a backhoe or track loader and placed in one or more piles around the site. Depending on the property location, these piles of debris may need to be hauled away by dump trucks. On larger or more rural properties, they may be buried on site well away from the home, or burned. Burning will require permission from the fire department in the municipality where the home is located and will also require monitoring.
Rough grading
If the lot is heavily wooded and several trees need to be removed, a bulldozer or track loader is next brought in to shape the property. Most of the dirt on the surface of the site is of high quality called “topsoil.” It is quite valuable. Grading will clear most of the topsoil away from the area where the home will sit and it will be piled up on site. Some of that soil will be used for backfilling the foundation. But a good deal of it can be used for landscaping, providing a nutrient-rich medium for grass and other plantings. Often the dozer must move the subsoil around to create a pleasant and efficient topography for the home site. A vehicle access path from the street to the building site (called the “road” in the early stages of lot prep) is usually cut in by the grader at this time as well. Some builders like to pour the concrete driveway for the home at the same time that the slab is poured. If that is the case, a little finer grading for the driveway is also done at this time, as long as the elevations have been fairly precisely set during rough grading. *
Staking the building site
After the grading is done, a precise staking of the building pad will be done. Similar to rough-staking, this task lays out the precise corners of the building pad. These stakes will be used as guidelines for setting the foundation footings.
Other tasks
At some point during the site preparation phase, utilities are brought on to the property. Once the home site has been identified, power, sewer, and gas companies will be contacted so they can bring their utilities to the site. This can also be done by the development contractor if that has been specified in the contract. If the home is to be on a septic system, the septic contractor will dig and install collection tanks—often two or three of them, perhaps a sand filter, and a tight line leading to a large drain field. Any necessary electrical work for pumps and alarms will be roughed in at that time. Scheduled inspections by the building department will take place for each of the major tasks, such as grading and septic work, before the subsequent phases begin. #
* Finish grading is done later on in the project, after the construction of the home is completed. A large, commercial grader is often used for this task, but occasionally a smaller machine is used for even finer shaping of the landscape (see Final Grade under FINISH WORK later on in this handbook).
# Some developers install the septic system toward the end of the project, after the final grading has been completed.
FOUNDATION
SINCE the quality of the foundation will determine how well your home will stand up to soil movement, care must be taken in designing your foundation, not only for the house but also for its geographical location. An engineer will crunch all the numbers and come up with specifications that will be used by the architect when drawing up the structural blueprints. There are basically three different types of foundations. The type used will depend on a number of factors: the preference of the homeowner, what style of home is being built, the geographical location of the home, the topography of the site, and the guidelines of the governing authority. They are: slab-on-grade, crawlspace, and full basement piling foundations. No one type is better than another; they all serve their purpose. However, one type might be more practical budget-wise or provide more comfort, depending on in what part of the country the house is being built. Each type of foundation has its pros and cons.
Slab-on-grade
As the name indicates, this type of foundation is just a large, relatively thin slab of concrete attached to the soil at ground level (grade) and supported by footings around its perimeter and in bearing areas. The slab-on-grade is typically the least expensive type of foundation if staying within a budget is a top priority. It also requires the least amount of maintenance. Generally speaking, slab foundations will be one of three common types: conventional rebar, rebar with bellbottom piers, and post tensioned slabs.
Crawlspace
Again, the name gives a good indication of the construction. With this type of foundation, the house is elevated a few feet off the ground, making it possible to “crawl” between the bottom floor and the grade. Crawlspace foundations may be supported by short poured concrete or cinderblock walls on which the bottom floor of the home is built. Access to utilities such as plumbing, electrical, and ductwork is easy, especially if the crawlspace is more than a few inches high from grade to framing. And, as the bottom floor is built out of wood instead of concrete and separated by an air space, floors tend to feel warmer. However, crawlspace foundations are prone to moisture intrusion, leading the growth of mold and mildew. Extra cost will be involved in providing vapor barriers and insulation to cut down of this potential buildup. And like slabs, the crawlspace does not provide a lot of protection from inclement weather.
Homes built on pilings
Piling foundations are a type of “deep foundation” system that transfers building loads to the earth far below the surface. They are commonly used in coastal regions and areas susceptible to storms and flooding. Pilings are vertical structural elements that are driven deep into the ground with a pile driver so that they rest on or in bedrock. They can be constructed of a number of different materials. For instance, wooden pilings are made from the trunks of tall trees; concrete pilings are poured concrete columns reinforced with rebar; and steel pilings are typically constructed from either tubular steel or I-beams. Pilings are connected together by a pile cap. These then provide a stable foundation on which the home will be built and elevated above the hazard zone of potential storms. The framing of the home then follows the general procedure as that of crawlspace foundations.
Building the frames
Slab-on-grade foundations are the easiest to frame. A backhoe is used to excavate out the proper width and depth for the footings. 2x8s, 2x10s, or 2x12s are used as form boards to create a border into which the concrete will be placed. With the “T-shaped” application, the slab is poured at the same time as the footings, connected by reinforcing bars (“rebar”). A “floating” foundation is typically used when building smaller structures such a home additions, garages, etc. With this type of application, a short “stem wall” is poured as part of the footings, and once it has cured, the slab is poured between the stem walls. With smaller applications such as this, sheets of reinforcing mesh, called “remesh” may be used for slab reinforcement instead of rebar.
Crawlspace foundations require considerably more work. Following the perimeter outline created with metal stakes and mason’s lines, the backhoe operator excavates out the trenches for the footings to the correct depth and width. The stem walls are considerably higher than those used in slab foundations and typically reach from a couple to several feet above the grade level. The first floor of the house will be built on top of the stem walls. The shapes for these walls are created by attaching ?” plywood to a framing structure made from 2x4s and 2x6s. Building departments for some cities require that blue sleeves be attached to the framing material that extends below grade for additional protection.
Because wet concrete will tend to want to “blow out” the plywood-framed walls when poured, wooden braces are staked to the ground and screwed to the wall framing every few feet on both sides of the wall frames. Rebar is placed at regular intervals throughout the framing structure and tied off. Access holes to underground utilities such as plumbing and electrical are cut into the structure at this time. Finally, additional bracing is placed on the top of the stem wall framing every few feet to ensure that the frame does not move or warp when (extremely heavy) concrete is poured into them.
Once the footings and foundation have been framed, the first of the building inspections is called for. The type and timing of the various inspections are specified in the building permit that was obtained for the home’s construction. At this time, the governing authority, usually the county in which the property is located will send out an inspector to examine the work that has been done to ensure that the foundation, especially the footings, are up to code for the area. Once that inspection is signed off, the concrete can be poured. This is also the typical timeframe specified on the Gantt chart for the lumber to be delivered to the building site in anticipation of the commencement of the framing phase once the concrete has cured.
Pouring the concrete
The pouring of concrete is also called “placing.” The concrete for smaller or easily-accessible homes is often placed with just a concrete mixing truck. The truck backs onto the property as close to the first area to be poured as possible and one or more trough chutes are attached to the back of the truck to be able to reach the forms. Larger, complex, or difficult-to-access homes usually use a concrete pumper. This is piece of heavy equipment that is stationed at a central point on or near the property. The long booms on these machines can reach lengths of 200 feet, and the pumping end can be moved by the engineer running the machine and be easily maneuvered by the concrete worker on the ground. The pumper is situated on the property so that a concrete mixing truck can back up to it and dump its load into the pumper’s reservoir. When one truck is empty, another one takes its place. In this way, the workers have a continuous flow of concrete until the entire foundation is filled, considerably reducing down time.
Once the concrete has been placed, it must be consolidated. The process of mixing and pouring entrains a lot of air into the concrete which can eventually lead to “bugholes,” uneven settling, or even complete failure. To remove the air bubbles, a worker inserts a large, industrial vibrator into the wet cement every 8-10” and pulls it out slowly. The vibrating action liquefies the concrete and allows the trapped air to escape to the surface.
While the concrete is still wet, anchors bolts are typically placed around the perimeter of slab foundations or at the top of stem walls. Although there are a number of different anchoring systems available, the most common are L-shaped galvanized rods which are threaded on the long end. These are sunk into the wet concrete at regular intervals (specified in the blueprints) and become highly secured when the concrete dries. During framing, wooden framing members (called sole plates in slab construction and when placed on top of an already-framed floor and sill plates when attached directly to the stem walls in foundation construction) will have holes drilled in them and be placed over these bolts on top of the concrete and will serve as the bottom framing members for exterior walls. These are secured with galvanized nuts and washers or bearing plates.
Finishing and curing
There are several steps to finishing and they must be done at specific times to ensure the best job possible. Usually, concrete is slightly overfilled within the forms. After pouring and vibrating, the excess concrete is removed in a process called “screeding.” A piece of lumber, typically a 2x4 somewhat longer that the form is wide, is placed on the tops of the forms and moved back and forth in a sawing motion. This not only removes the excess concrete, but it gives a rough level to the surface. The same thing is done with a slab, but it takes at least two workers to operate the screed. Then, with a wooden trowel or magnesium float, the surface is smoothed out.
Now it is time to wait. Water will start to pool on the surface. This is called “bleed water.” Time must be allowed for the bleed water to evaporate. This could take anywhere from 20 minutes to several hours, depending on temperature, humidity, and wind. Then the surface can be further smoothed out with at finishing trowel or float. Another waiting period follows finishing, this one for “curing.” Proper curing allows concrete to solidify evenly and produce the strongest slabs and footings. Part of the curing process is keeping it moist. This can be accomplished by misting it regularly or covering it with a wet, breathable fabric such as burlap. Doing so prevents the surface from drying before the base, creating a better, longer-lasting product. Slabs can be walked on in 4-7 days, but it takes 28 days for concrete to fully cure. The contractor may use an admixture to speed up the process. Check with him if you have any questions. In many municipalities, a slab inspection is called for after the concrete is poured if a slab-on-grade foundation is being used. After that, framing may begin.
How draws are handled
Rather than getting paid in one lump sum after the project is complete, contractors are usually paid in “draws.” At specified milestones along the way, such as after the electrical rough-in is complete or after the drywall has been finished, the builder is paid a predetermined portion of the entire contracted amount, plus any work orders that have been approved and completed up until then. Typically, at some point between the footing inspection and the beginning of framing, the first draw is paid. Subsequent draws are referenced in this handbook, but they are just general guidelines. Some contracts may specify more or fewer draws, and they may be paid at different points in the construction project.
FRAMING
THIS is the stage where the house really begins to take shape. Sometimes compared to a skeleton, the wood “bones” of the home consist of a number of different sizes of dimensional lumber, each specific to its own purpose.* 2x4 and 2x6 boards are used for framing walls, 2x8s for ceiling joists and roof rafters, 2x12s for floors, and laminated beams wherever large areas need to be spanned. These are all cut in place and attached together using appropriate fasteners, typically nails and screws, following the specifications outlined in the architectural drawings. Metal accessories are almost always used for attachment, reinforcement, and bracing functions. These include joist hangers, bolted holdowns, tension ties, bearing plates, gussets, and hurricane ties, as well as many others. Since there is no one “right” way to build a house, different architects, builders, and subcontractors may use similar materials in different combinations to frame the same house.
Framing the floor
In slab construction, the concrete itself makes up the floor. For crawlspace foundations, the floor is framed out of wood on top of the stem walls. Sill plates are first anchored to the foundation (see Pouring the concrete above). Stringers a used to support the floor joists. These tie in to columns or concrete blocks. The floor joists, usually 2x12s, are laid on edge on top of the stringers following the specified spacing, typically 16” on center. These span from one stem wall to the opposite stem wall making up a section of the home. Most building codes allow unsupported spans of no more than 16 feet. For spans exceeding this limit, intermediate weight-bearing girders are used which are supported by piers or by footings and foundations built when the rest of the concrete was poured. The floor joists are set in place by either toe-nailing or by using metal hangers. The ends of all the joists are tied together with additional 2x12s, creating a box that sits on the foundation, flush to its outside edges all around.
After the floor is framed, it is covered with 4x8 sheets of 3/4" decking, either plywood or oriented-strand board (OSB). This decking is referred to as the “subfloor.” Often these sheets are tongue-and-groove, enabling a tight fit between sheets and cutting down on the possibility of having squeaky floors. The decking is laid perpendicular to the joists with joints overlapping at least two feet. The sheets are attached nails, the size and type which have been designated in the blueprint instructions. Screws are occasionally called for in some higher-end homes. Though considerably more expensive to do, this usually completely eliminates floor squeaks. The decking is trimmed flush with the floor box, creating a highly stable base on which to construct the rest of the home. Additional stability is achieved with wood or metal blocking which is installed between the floor joists at regular intervals indicated in the plans.
Many contracts call for the second draw to be paid upon completion of the framing of the floor, also called the “deck.” If a second story is going to be built, the third draw is usually paid after the first floor walls are framed and the second floor deck has been built.
* While metal stud construction is becoming more and more popular as an alternative system of home building, this handbook focuses on what is by far the oldest and most common method in the country today, wood-stud framing.
Framing the wallsA primary difference between slab and crawlspace foundations is how the walls attach to each. With a
slab foundation the sole plate of a wall is bolted to the slab, whereas with a crawlspace the sole plate of the wall is nailed or screwed to the subfloor structure that was built on those stem walls.
Laying out a wall is a very interesting procedure. It is basically done by creating templates on wooden framing members with a carpenter’s pencil. For the sake of simplicity, let’s assume that we are building on a foundation and attaching the wall to the already-built floor. Two pieces of lumber, usually 2x6s, are cut the length of the wall being built and laid side-by-side on the floor near the intended location of the wall. A carpenter’s square and pencil are used to mark out on the boards where the studs will be placed in the wall. If there are doors or windows in the wall, they are laid out at the same time, allowing for placement of king studs, trimmer studs, and cripple studs in appropriate places.*
These boards, called plates, are then turned on edge and separated by the height of the wall and wall length studs are placed between them in the locations drawn out during layout. King studs and trimmers are usually placed at this time. The studs are then attached to the plates using a hammer or nail gun, inserting the nails through the outside of the plates and into the studs. When all the parts are attached together, the framed wall is stood up, usually by two workers, and set in place at the edge of the floor.
The wall is secured by nailing the sill plate and temporary bracing is attached to hold the wall square and plumb. This process is repeated for the rest of the walls making up the ground floor of the home. Walls over 16 feet long are usually framed in sections and then those sections are joined together when the walls are raised. When there are two or more workers doing the framing at the same time, often each will work on different walls and then help each other raise, attach, and brace them. When attaching the ends of walls together, the end studs on each of the walls are nailed together, creating a strong corner.
Almost all exterior and load-bearing walls have a double plate on top for additional strength and to allow room to attach the drywall to the top after the ceiling drywall has been installed. More often than not, all of the interior walls also utilize the double top plate as to facilitate drywall installation. If double plates are being used, they are typically installed after the walls have been raised and the corners tied together. The topmost plates are cut to overlap the lower plates at the corners and cross over abutments in long walls to provide strength and durability to the overall building.
Once the walls are in place, the workers go back and frame in the window and door openings. For load-bearing strength as well as earthquake resistance, headers are placed over all doors and windows. These are single pieces of 4-by or 6-by lumber or composites of wood members made up of smaller pieces of lumber laminated together. These laminated headers are usually built in place by the framers. They are attached horizontally above the doors and windows and rest on the trimmer studs. If the header does not fill the entire space about the opening and the top plate, small pieces of 2-by lumber called cripples are placed above the header to maintain framing layout. With windows, framing is also installed underneath the window opening in the form of a double plate and cripple studs are placed between that and the sole plate to continue the layout.
* Trimmer studs run vertically along the framed opening for doors and windows and support headers. King studs are attached directly alongside the trimmers and run the full height of the wall. Cripples are short studs that are placed on layout under windows and sometimes over windows and doors.
After the walls are built and set, they need to be braced. If exterior sheathing is not going to be used, bracing can be accomplished using 1x4 “let-in” braces or long coils of metal strapping. This is often referred to as “hurricane bracing.” Let-in braces are created by temporarily nailing a 1x4 to the outside of the wall running diagonally from one top corner to the opposing bottom corner. The location of the 1x4 is marked with a carpenter’s pencil on the studs. The brace is removed and 3/4" saw cuts are made at the marks. The pieces of word knocked out and the notches are cleaned up with a wood chisel. The 1x4 is then reinstalled into those notches and attached using 8d nails, two per stud. An alternative bracing method is to use 16- or 25-guage coiled metal strapping attached in a similar way diagonally along the outside of the wall. The thinness of this strapping usually eliminates the need to “let in” or cut notches in the studs. Of course, if sheathing is to be used on the exterior of the house, neither of these methods are necessary because the sheathing acts as its own bracing when attached.
Detail work
After much or all of the framing has been done, it is time to go back and do some “rough-finish” detail work. A hand or power saw is used to cut a section of the sole plate out between trimmer studs at all the doors. Additional bracing is placed at strategic places in the frame. Additional studs may need to be installed at inside corners to create backing for drywall attachment. Pieces of 2-by material or 3/4" plywood are installed when tubs and showers are going to sit and where wall-hung appliances are going to be located. Some builders also like to install short pieces of wood (called “scabs” or “cleats”) to the bottom corners of walls to make it possible to properly install baseboards without having to place the nails too close to the ends and risk splitting. Other details may be spelled out in the architectural drawings or may be requested by the homeowner or required by the builder.
Roof design
Roofs are framed during the same phase as the rest of the house, and usually by the same crew. The roof covering is considered a separate phase and in large tracts is often done by a different crew. Building roofs is one of the more complicated jobs, especially with today’s trend in upper-end home design employing lots of angles, valleys, dormers, and eave details. And while “stick-framing” roofs is still the norm, many builders are using pre-built trusses. Trusses are complete units of the “ribs” of a roof and are constructed in a factory according to blueprint specifications. They often require much smaller lumber than built-in-place roofing, usually using 2x4s instead of 2x6s or 2x8s. Each of them has a series of “W” braces built in them which stabilizes and strengthens the trusses. Typically, trusses are more expensive than traditionally-framed roofs and require more manpower to install since they are usually hoisted into place by a crane. However, they do save a lot of building time, especially when constructing multiple homes.
There are five basic roof designs, and homes often employ more than one design into a single roof. They are gable, hip, shed, gambrel, and mansard. Gable and hips roofs are the most common in home construction. Shed roofs are seldom used in full-size houses; they are generally limited to garages, shops, and sheds. The gambrel is a traditional barn-style roof. Mansards are reminiscent of English-style buildings and are not as commonly used in today’s modern designs. Variations of these basic designs are often used to create interesting rooflines. For instance, the “saltbox” is a design that can commonly be found in the New England states. It is a basic gable roof with one side longer than the other.
Geometry comes into play in roof design. The triangle is the most common geometric design element in roofing, but rectangles and trapezoids can also be found. For example, a simple gable roof consists of two right-angle triangles joined together on their shortest sides to form an isosceles triangle. Variations on this simplest of designs might produce and equilateral triangle or even a scalene triangle, one with no equal sides. However, roofing employs many non-geometric terms in its design such as rise, run, span, pitch, and line length. Putting a number to each one of these words is what gives us the shape of the roof.
The term most commonly associated with roof design is “pitch.” Pitch refers to the angle that the roof slopes up toward the center from its starting point at the top plate of the outside wall. Typically, the roof pitch is 1/3 or 1/4 of the entire span of the roof. The number of inches that a roof rises above the plane of the housetop in a “run” of 12 inches is the pitch. So, for example, if you were to measure along the top plate from the outside wall to the center of that wall and then measure from that point up to the top of the roof (called the “rise”), you can figure the pitch of any roof. If the run is 12 feet and the rise at that point is four feet, the pitch would be “four-in-twelve.” This means that the roof rises four inches for every 12 inches of run. In this case, the pitch is four feet in 12 feet. This expression is notated “4/12.” The pitch of the roof is illustrated with a small detail on the elevation of the blueprints showing an upside-down right angle triangle just above the roof line with figures for the rise and the run on it.
“Span” is the entire distance from one supporting wall to the other. The rise is typically half that distance, the point where the gable changes directions at its peak. The line length might be referred to as the hypotenuse of the right triangle: the distance from the supporting wall to the top of the peak. Higher-end homes may employ multiple roof pitches with sections joined together to create a pleasing look.1
Whereas there is some latitude in one’s choice for roof design, the pitch of the roof is often determined by location and climatic conditions. For instance, snow load is a critical factor on many of the northern areas of the country. It is not uncommon to see roofs with 8/12 or even 12/12 pitches because the steeper slope makes shedding snow easier, thus not overtaxing the ability of the roof to carry that load. In warmer climes, roofs with pitches as low as 3/12 are common. Pitches lower than 3/12, however, require a different type of roof cover than traditional roofs do.
Framing the roof
If the roof is to be stick-built, ceiling rafters of 2-by lumber are attached to the top plates on the layout designated in the architectural drawings, usually 16” or 24” on center. Layout starts from the outside edge of one wall and continues to the opposing wall, the last bit of spacing typically being less that 16” or 24”. A final rafter is placed at the edge of the wall to match the rafter at the beginning of the layout. These boards are either toe-nailed down or attached with some form of hurricane tie. *
* If the room on which the roof is being built is to have a “vaulted” or “cathedral” ceiling, this step is omitted so that no framing members obstruct the openness of the room’s design.
Next, roof rafters are cut. Often, all of the boards to be used for each side of the gable are cut at one time so that they can be erected quickly. The roof rafters will need to span the entire length of the run (the peak down to the wall) plus an additional amount to create the eaves. Boards slightly longer than this span are prepared, installed, and then trimmed. Most stick-framed roofs employ a “ridge board,” a long piece of 2-by lumber at least one size larger than the rafters being used that will run the length of the ridge. The cut rafters will be tied into it. Ridge boards provide stability and make the job of framing the roof easier.* They are initially set and held in place by temporary braces that run from the floor of the room to the peak of the roof with cleats attached to hold the board in place. These braces are removed once the roof is built.
Two cuts have to be made in each roof joist before it is installed. An angle is cut at the top of the rafter to enable it to fit tightly against the ridge board. This is called a “plumb cut.” Toward the bottom of the rafter, at the point where it will rest on the top plate of the wall, a “bird’s mouth” is cut. This is notch conforming to the shape of the top of the wall that is cut into the board, the length of which is approximately the same size as the width of the top plate. This notch will enable the rafter to sit securely on the top of the wall, eliminating its natural inclination to slide down. Once set in place, the rafter is attached to the ridge board and to the top plate of the wall as well as to the ceiling rafter against which it rests. These attachments can be made with nails, screws, or hurricane tie plates or a combination of these.
Making these cuts is a skill that is learned over time and with much practice. For generations, a simple framing square was used with success depending on the builder’s complete understanding of the geometry involved and how to position the square to make precise cuts. Several years ago, a compact tool called a “speed square” that has roof pitches and other important figures engraved on it made the job much easier. Today, an innovative new tool called the C.H. Hanson Pivot Square has simplified the process even further. With any method, an accurate layout of the roof rafters is essential. They carry the roof which is the first defense against weather and therefore they need to be as stable and secure as possible.
Once all the roof rafters are in place, securely attached, and appropriately braced, the ends of the rafters that will create the eaves (called “rafter tails”) are trimmed. This is done by snapping a chalk line from the first rafter on one end of the wall to the last rafter of that wall. This line represents the edge of the finished eave. A speed square is used to mark lines with a carpenters pencil on each rafter at the exact same angle as the angle of the plumb cut at the top end of the rafter that is attached to the ridge board. Then, using a circular saw, one of the workers goes back and trims each rafter tail (called “tail cuts”) along that line. Alternatively, some builders make all the tail cuts at the same time that the plumb cuts and bird’s mouths are cut. If boxed soffits are to be used in the house design, level cuts are also made to the rafter tails to accommodate them.
Gable ends typically have the roof overhang them. This overhang is usually somewhat shorter than the eave but it can be any length depending on the architectural design. Since the rafters comprising the edge of the gable overhang have nothing to be attached to, structural elements known as “lookouts” are built to carry them. Notches the depth of 1-by or 2-by material are made in the edge rafter at regular intervals. A piece of 1-by or 2-by lumber in inserted into that notch and placed up against the second rafter. This piece of lumber is attached to both rafters with nails and it is trimmed off at the distance from the wall that the roof is to overhang. A final piece, called a hanging or “fly” rafter is attached to these lookout boards, giving the roof a pleasing, finished look.
* If the roof is being built with trusses, a ridge board is not used. It is unnecessary because the trusses come as complete units and are simply dropped in place and attached. However, a “strongback” running the length of the roof is attached to the underside of the trusses at or near the peak. An alternative method of strengthening the truss roof is by installing blocking, short pieces of lumber between the peaks of each of the trusses.
Most roofs employ more than just the simple gable design illustrated here. But the same geometric principles and construction techniques are used in other designs as well, with adjustments being made as the style dictates. Hip roofs, for example, do not have gable ends and the ridge board, which is called a “hip rafter,” is installed at an angle following its own roof pitch. The rafters that are attached to these boards are called “jack rafters.” Other designs follow similar variations but still use standard building methods.
Installing fascia
Although fascia might be considered part if the finish work, it must be installed prior to the roofing so that drip edge, underlayment, and roofing material can cover it. The word fascia comes from a Latin word meaning “band,” and in this application refers to a board that finished off the edge of a roof. Usually made of made of 1-by, 5/4-by, or 2-by primed whitewood, fascia is attached to the rafter tails, thus covering up the raw end of the rafters and provide a clean, attractive look to the house as well as a base for attaching rain gutters. Fascia is usually also attached to the outermost gable rafters and in this case they are called “barge boards.” Fascia usually comes pre-primed although some builders prefer to use unprimed cedar boards for fascia. In either case, fascia boards receive their finish coat when the rest of the trim work is done.
Detail work
Once the bulk of the actual roof structure is completed, a number of details need to be tied up to finish off the job. Permanent bracing is installed in critical places and all temporary bracing is removed. Several areas of the roof are blocked. Stick-framed as well as truss roofs have short pieces of lumber placed between the rafters at alternating, regularly-spaced locations, following the blueprint specs. If boxed soffits are to be employed, backing is installed to accommodate those. If the eaves are to remain open, “bird blocking” is usually used. These are pieces of 2-by lumber cut to fit between rafters and have holes bored in them, usually 2” to 3” in diameter. Metal screening is attached to the back side of these boards and they are installed between rafters at the wall line, perpendicular to the roof angle. Hurricane straps may be used and other types of security accessories installed as called out in the blueprints.
Those who are designing and building their own home have several methodology options open to them. Particularly if the owner/builder is going to be “swinging a hammer” himself, he would want to have the home design and construction protocol created which would fit his personal preferences and abilities the best and still stay within local code guideline. When working with the architect, these preferences should be clearly spelled out and will be included in the blueprints.
ROOFING
ALTHOUGH this phase could seemingly be included in roof framing or finish work as well, it is really a stand-alone phase. In some parts of the country, once the roofing is installed, the house is considered to be “dried in,” meaning that one can stand inside the house in the pouring rain and not get wet. Even though the addition of siding, windows, and doors would make for a much drier product, roofing installation is still considered a major milestone in the construction of a home.
Material options
There are number of roof covering options available, from generations-old methods to new, innovative systems, with others being developed and perfected all the time. For the purpose of this handbook we will consider the most typical of the tried-and-true materials, composition shingles. Then we will include comments on some of the more common options to comp shingles at the end of this section.
Installing sheathing
Before the actual roofing material is laid, a substrate must be installed on which the material will rest. In most cases, that substrate is CDX plywood or oriented-strand board (OSB). Standard thickness is 1/2", but other sizes may be used as desired or required. Since this flat material (called “sheathing”) is going to rest on the roof trusses that have been installed, it is important that those trusses are on a fairly even plane with each other. Before the sheathing is installed, a straightedge is placed over various parts of the roof. Any of the top rafters (or truss “chords”) that deflect more that a fraction of an inch must be shimmed. This will prevent water from pooling in areas with low spots. Bowed or twisted rafters and chords should be blocked to remove the bend.
After the trueness of the nailing surface has been established, the sheathing is installed. Starting at the outermost edge of the eaves, sheets are laid down perpendicular to the rafters. To ensure straight installation, especially on long roofs, a chalk line is snapped at 4’ up from the edge of the eaves and the first course of sheathing is set on that line. That first course also establishes the straight line for the rest of the courses to follow. A 1/8” gap must be left between sheets, both on the edges and at the butt ends. There are spacers that are available to be used for this purpose, but most builders simply use a 16d (“16-penney”) nail as a spacer. Edge clips are also available to ensure proper alignment of sheets between rafters, and also act as spacers.
The joints between sheets must be staggered a minimum of 24”, but staggering 48”, a full half-sheet, is preferable. Panels that overhang the edge of the roof are trimmed off flush with the outside rafter. Sheathing is attached to the rafters using 8d common nails, spaced 6” apart on the ends and 12” apart in the field. Areas that are prone to high winds may require additional fasteners. Nails should be 3/8” from the ends and the edges of the panels. Courses of sheets are installed until the peak of the roof is reached. The last course is usually less that 48”, so those sheets are rip-cut so that they are centered on the ridge. When the opposing side of the roof is sheathed, the final courses meet at the top with just a fraction of an inch separating them. If a ridge vent is going to be installed, the top courses are ripped to leave a 2” space between them and the peak over the run that the ridge vent will be installed.
It bears mentioning at this point that once the wall framing is completed, it is a good idea to have the plumber begin his rough-in. By doing so, all the venting pipes will already be installed by the time the roof covering is done. It is usually simpler (and safer) for the roofer to cut a hole in the sheathing as he is laying it than for the plumber to climb up on the roof to cut the hole after the fact.
Installing drip edge
A metal flashing called a drip edge is used to divert rainwater away from the fascia boards on the roof. As the names implies, drip edge has a small bend in it called a “kicker” that forces the water to drip straight down instead of running onto the fascia which can cause rotting over a period of time. It goes on before the roofing and is covered by both the underlayment (see below) and the roofing material. Drip edge is attached using 8d galvanized nails to the sheathing along the eave edge first and then up the gable ends also known as “rake edges.”* It is best to hold the drip edge about a 1/4" away from the fascia to prevent a phenomenon known as surface tension to cause the water to run back up the drip edge and onto the fascia. Where drip edges meet on a run, they are overlapped by at least two inches. Where drip edges reach a hip or a valley in the roof, they are trimmed to create tabs which overlap each other and extend over the hip or valley by a foot or so.
In addition to drip edge, there are a number of other flashings that may be used depending on the roof design and blueprint callouts. For instance, large sheets of W-shaped flashing may be installed in valleys. However, the application of some roofing materials such as composition shingles does not require it. Step flashing is used around chimneys and dormers but must be installed with the roofing material. The same is true of specialty flashings for roof penetrations and ventilation covers. Roof-to-wall flashings are used when the top of side of a roof meets an exterior wall. Skylights usually come with specialized flashing kits.
Applying underlayment
The next step is to cover the sheathing with a waterproof material called underlayment. Although several specialized types of underlayment are on the market, standard roofing felt, commonly known as “tar paper,” is the industry standard. More technically known as self-adhering polymer-modified bitumen sheet underlayment, this material helps to minimize the sheathing’s exposure to weather. It comes in 36”-wide rolls and is usually printed on one side with white lines which can be used for aligning the roofing material. Most codes call for 30-pound (30#) paper, but 15-pound (15#) paper is allowed on some buildings.
Although some roofers prefer to use 1” galvanized roofing nails, or even special roofing nails with orange plastic washers, most find it quicker and easier to use staples, and most codes allow that. A special staple gun called a “hammer stapler” is used for this purpose. It is like a regular staple gun on the end of a hammer handle. By using hammering motion similar to one used to drive nails, a roofer can apply dozens of staples to the tar paper in a very short amount of time.
* There are differing viewpoints on what order drip edge is to be installed. In multi-home production, the eave edges and the gable edges are done at the same time, before the underlayment is installed. This is usually done to save time and keep production flowing. However, it is a best practice to install the eave edge first, then run the tar paper over it and up to the edge of the gable, and then attach the gable drip edge over the paper and down to the lip of the eave edge. In building a custom home, this is by far the preferable technique.
Tar paper is rolled out along the eave from one gable end to the other and overhangs the drip edge by 1/2". A chalk line is snapped on the sheathing 35-1/2” up from the drip edge to create a line on which to place the starter course of paper. After the first course of paper is run, it is trimmed off and the rake edge. The next course, and all subsequent courses, overlaps the previous course by at least 8”. When the peak is reached, the paper overlaps the peak 8”. The top course of paper from the other side of the ridge then overlaps this paper by 4”-6”. If an opening for a ridge vent has been cut, the paper is trimmed out of that space. The underlayment is cut around all roof penetrations. When working with a hip roof, the paper is run to the peak of the hip on both sides so that edges fit snugly. Then another piece of underlayment is applied vertically from top to bottom, overlapping each side of the hip by 18”. Although the common practice is to lay all of the tar paper and then begin installing the roofing, some roofers feel it is more expeditious to run a couple of courses of paper and then start applying the shingles. When coming within 6” of the top edge of paper, another course or paper is run followed by another course of shingles.
Underlayment needs to be kept as straight and parallel to the eave as possible. Sometimes chalk lines are struck for each course. Others use the lines printed on the paper as a guide. Tar paper also needs to be kept flat, eliminating all wrinkles, creases, and bubbles along the way which could lead to the roof looking bumpy once the shingles are attached. Paper should be attached with at least three staples in the field every foot or so.
Applying WSU
In areas of the country where rainfall and freezing temperatures are common in the wintertime, waterproof shingle underlayment (WSU), also known as ice guard, may be used. The entire roof can be covered with WSU or just the parts that are susceptible to ice dams and moisture intrusion such as eave overhangs and valleys. WSU comes in rolls similar to tar paper, but it has a self-sticking side that is applied to the sheathing. The WSU is rolled out and laid in place, the paper backing is removed from the lower half of the sheet, and then it is pressed into place, taking care to eliminate bubbles and wrinkles. Then the top half of the sheet is folded down and the rest of the paper backing is removed as the sheet is pressed into place. When covering a valley, a piece of WSU is cut that runs from the valley peak to the eave. It is centered on the valley. One side is folded over, the paper backing is removed, and it is pressed back into place. Then the process is repeated with the other half.
There are several other types of roofing membranes on the market and each serves its purpose. Many are part of an entire system that works together. They are most commonly made from synthetic rubber, thermoplastic such as PVC, and modified bitumen. Most of them are “self-healing,” meaning that they seal tightly around roofing nails and small cuts. Although once found almost exclusively in commercial construction, these membrane systems are now commonly used in home building.
A fourth draw is often paid upon completion of the roof framing and roof decking installation. Some contracts call for payment to be made prior to installation of the roofing material; other are paid after, often depending on the type of material being used. Another variation in the draw schedule calls for payment to be made after the roof is framed and the exterior doors and windows are installed. These details are specified in the contract and also itemized on the Gantt chart.
Composition shingles
Roofing shingles used to be made out of asphalt and modern shingles are still called “asphalt shingles” at times. Several years ago, the move was made to composition shingles that have a fiberglass mat at their center and that mat is coated with asphalt and mineral fillers. For that reason, composition shingles are also called fiberglass shingles. Installation of composition, or “comp,” shingles is easiest of all the various types of roof coverings. And, installed properly, they are arguably the best defense against the elements of all the different materials. As such, today they are commonly used in construction of even the highest-end homes.
Comp shingles are usually one of two different types, 3-tab and laminated. As the name implies, 3-tab shingles are sheets of material that have been manufactured with three tabs of about one foot each on the lower half of the sheet. This is the part of the sheet that is left exposed during installation. When aligned, they provide a pleasing, uniform texture to the roof. Because the final product is relatively flat in appearance, 3-tab shingles are typically used on smaller homes as well as outbuildings and other structures. Laminated shingles, also known as architectural shingles, have two or three layers of fiberglass material laminated together with cutouts in each layer to add depth. When installed, they give the roof a thick, highly-textured look. For that reason, they are well-suited for larger and higher-end homes. Laminates are usually considerable more expensive than 3-tabs. All commercial composition shingles come with a 25-year to lifetime warranty.
Composition shingles are 36” long and are applied end-to-end in cascading courses parallel to the eaves. They are started at the eave edge and worked up toward the ridge similar to underlayment installation. Shingles are attached with 1” to 1-1/4” galvanized roofing nails. A pneumatic gun may be used which employs either nails or staples. They can be cut from the back side with a regular utility knife or from the front using a knife with a special hooked roofing blade. Composition shingles are designed to have a 5” reveal meaning that each course is installed 5” above the previous course. Although imperfections in line trueness are difficult to see from the ground, it is still a best practice to try to keep rows as straight as possible. To this end, chalklines are usually snapped for each course 5” apart or at least every other course. The white lines printed on most tar paper can be used as a guide, but if they are used it is imperative that trueness be checked on a regular basis. This is done by hooking a tape measure on the eave edge of the first course and ensuring that all the courses align with the tape in 5” increments. Some roofers use a simple jig with a 5” offset to regularly check alignment.
Installing composition roofing
The initial course is called a “starter strip.” It will be completely covered up by the first top course. Its purpose is to provide a waterproof edge to the eaves. Without it, the underlayment would be exposed to water intrusion at the butt joints between shingles as well as the spaces between tabs in 3-tab shingles. A secondary but important function of the starter strip is to establish the 2-layer roofing system that will continue the rest of the way up the roof, making it aesthetically pleasing as well as waterproof.
Most composition shingle manufacturers now produce dedicated starter strip material in either bundles or rolls. Generally speaking, these are the most cost-effective type of starter strip if more than a short run of roof is being covered. However, a tried-and-true method that has been used for generations is to create your own starter strips by cutting a regular shingle in half the long way. For example, the tabs are removed from 3-tab shingles by cutting 7” off the top half of the shingle. These “home-made” starter strips are then turned upside-down so that the self-seal strip is near the bottom. When heated by the sun, this strip will soften and bond to the underlayment, making a solid backing for the first regular course. The starter strip is installed by aligning the bottom edge with the underlayment and driving three nails (or pneumatic gun staples) evenly across the top edge.
Once the starter strip is in place, the rest of the roofing may be applied. With 3-tab roofing, it is usually best to plan a layout prior to starting, but the traditional and most common layout is the “brick wall” style with slots between tabs alternating between courses. This is accomplished by shifting each successive course down by a half tab. Some roofers snap two vertical chalk lines on the roof that represent the 6” offset alternating rows have from each other. Each course that is started is lined up with one of those two lines.
The first shingle is set with the eave edge and one end lining up with the starter strip in one corner. Fasteners are applied at each end of the shingle and above the slots (on 3-tab roofing) just below the self-seal strip. Four fasteners on each shingle is sufficient. The second shingle is butted up against the first one, end-to-end, and fastened similarly. After several shingles have been applied down the run, a second course is started five inches up from the first shingle. The first piece of this course is shifted the equivalent of 1/2 tab or about 6” and the end of shingle is allowed to hang over the rake edge.
The rest of the second course is applied end-to-end in a similar way to the first. This process is repeated for the subsequent courses up to the top of the roof section. Each course will be stepped back from the previous one by 6”. Once the top is reached, or after application of several courses, a chalkline is snapped on the gable end from the eave to the ridge even with the drip edge or 3/4" from the fascia. The excess shingle material is then cut off at that line. In order to conserve shingles, those pieces are used to finish off the ends of the courses along the other gable. Then the roofer goes back and completes each course from the point where the steps begin. After one entire side of the roof is covered, the excess material is trimmed off the ends just as was done on the first rake edge.
Handling penetrations
In the course of applying material, several roof penetrations will be encountered. These must be sealed around carefully. All stacks, pipes, vents, and other penetrations will have some kind of flashing that is designed to seal them. These can be vent covers, pipe jacks and boots, conduit flashing, or any number of other sealing accessories. The shingles are run up to and just past the penetration with a hole or slot cut around the pipe or vent. A generous amount of roofing mastic is applied all around the bottom of the flashing accessory and then it is slipped over the pipe. The flashing is nailed down only where it will be covered by shingles. The bottom of the piece that is exposed should be left unnailed. The next course or two of shingles are then cut to fit around flashing so that they lay flat and do not run up the side of the flashing. Any exposed nails should be covered with mastic. Vents that cover attic ventilation holes are installed in the same way, with the hole cut out of the corresponding shingles.
Installing ridge cap
A ridge cap is used to finish off the roof peaks and hips. There are several ridge caps available on the market. Most shingle manufacturers produce caps that match their various colors and styles. When 3-tab shingles are used, however, simple and effective caps can be made by cutting shingles into thirds between tabs. The cuts are made at a slight angle so that the concealed edges of the pieces will not peek out from under the covering cap. It is usually best to used pre-made ridge caps for thick architectural shingle because, unlike flat 3-tab shingles, they provide shadowing and texture similar to the rest of the roof.
The caps are installed by first placing a starter piece about 7” long at one end of the roof and nailing it down securely. It should overhang the rest of the shingles by 3/4". Then the first full piece is attached on top of the starter piece perpendicular to the rest of the shingles and is aligned with the starter piece on the end. The rest of the ridge is then covered with pieces of cap material, leaving a 5” reveal on each piece. When the other end of the peak is reached, the final piece is nailed down securely and the exposed nails are covered with mastic. And alternative installation method is to run the cap from both ends toward the middle and then cover the center of the ridge where they meet with a final piece which is nailed in place and the exposed nail heads covered with mastic.
Other encounters
When the roofing meets the peak or a hip, one side of the roof is cut just slightly short of the peak. Then, when the other side is covered, the top course is cut to overlap the first side by no more than 4”. Ridge cap then finishes off the peak.
When a valley is encountered, such as where the roof changes direction, the shingles are run up the other side of the valley by at least a third of a shingle or 12”. The roofing can be installed on the other side of the valley one of two ways. Either the shingles can be trimmed off in a straight line running from the top of the valley to the eave (called a “closed-cut” valley) or the shingles from both sides can be interweaved to create the appearance of a continuous line of roofing courses running from one roof direction into the other. A less common method is the “open” valley in which a sheet of W-flashing is installed over the waterproofing membrane and the roof is installed over the flashing and trimmed in a straight line an inch or two from the center of the valley on each side.
When a hip meets a ridge, as all hip roofs do, one side of each peak is trimmed off at the peak line and the other side overlaps, no more than 4”. When all sides of the hip are done, ridge cap is used to finish it off. The final piece is cut to shape and slit so as to cover the roofing on all sides. Exposed nails are covered with mastic. When a dormer meets the roof, the valley is done as mentioned above. At the peak of the dormer, winged WSU is first applied. A split ridge caps is then attached. Finally, a sheet of WSU is used to cover both and is in turn covered by the next course of roof shingles.
When encountering a chimney, a combination of saddle, apron, and step flashings are employed to prevent moisture infiltration. They are applied in such a way so that water is always forced down by gravity and prevented from running back up by means of surface tension and capillary action. Generous amounts of roofing cement are used to ensure that all sides of the chimney penetration are waterproof.
A Note about racking
Racking is a roofing technique that is used primarily in large-scale production homes because it saves the roofer time. Racking involves cutting a number of shingles in two sizes, one 6” shorter than the other. Each size is installed alternately at the rake edge to begin a course and then another two or three shingles are added to each course. In this way, the roofing is installed vertically in columns instead of horizontally in rows. This technique saves the roofer time by being able to cover a large area without having to constantly move his tools or reposition his harness. However, this method often creates an undesirable condition called “pattern curling,” where shingles curl and blow in the wind at the points where columns join. This is caused because of the roofer having to lift the end of a course high enough on every other row in order to be able to insert and nail down the next set of column shingles. It is not a recommended technique, especially on custom homes, and should be avoided.
Installing metal roofing
Metal roofing has been used in areas with heavy snow loads for decades because of the ease in which it sheds snow. But it has quickly become a first choice for many owners and builders as an alternative to conventional roofing, both as for new construction and for re-roofs. It is now available in a wide array of colors, styles, and textures. And since it is relatively easy to install and covers a large amount of roof area in a relatively short time, it is a favorite for do-it-yourselfers. However, unless you are a roofer by trade, or at least have had some experience with metal roof installation, it would likely be best to leave it to the professionals if it is part of an entire home construction project. That way work does not have to stop or be slowed down or time-shifted to meet the owner’s personal schedule.
Unlike other roofing materials, metal roofing is susceptible to scratching. Therefore, it is often installed after any siding, stonework, stucco, and painting is done so as to minimize the need for walking on the roof, thereby preventing unnecessary dents and scratches.
The framed roof is covered with sheathing and underlayment just as in other roofing types. Before installing the metal roof, all penetrations should have been run through the roof with proper flashing and roof jacks installed. Drip edge is installed around the perimeter, the eaves first followed by the gable ends. It is attached using regular 1-1/4” roofing nails. On a straight gable roof, layout can begin at either end. On a hip roof or one with unusual angles or cutouts, it is best to begin in an area with the longest distance between the peak and the eave where full sheets can be installed without cuts. If the run of the roof is more than 12 feet, the first course begins at the eave. The ends should overhang the eaves by 1"-2”.
Subsequent sheets are then added to the course. Metal roofing has a series of ridges which give it definition and each edge is designed to overlap other sheets by 2”. One edge on each sheet has a ridge with a small lip. The other edge without that lip is placed over the top of the edge on the previous sheet. In areas subject to a lot of rain or wind, silicone sealant or butyl tape is applied at overlaps. Sheets are fastened to the sheathing with 2” screws that have special neoprene washers built in. These seal against the metal, preventing water intrusion. The screws are installed on the flat areas about one foot apart in a row up the entire sheet; rows are spaced about two feet apart. Closer spacing may be necessary in high-wind regions. Some metal roofing manufacturers produce sheets that have hidden clips which are used to secure the panels.
After the rest of the first course is run, a second, usually shorter, course is added which overlaps the first course by at least 4” and may have sealant applied between the panels. When all the full sheets have been installed, hip roofs are covered with sheets that have been cut at an angle along hip lines so that both sides of the roof meet at the ridge, leaving about a 1/2" space between them. Metal roofing is cut with tin snips or a circular saw fitted with a metal-cutting blade. If there are valleys, valley flashing is attached first and then the panels are cut at an angle so as to maintain a space between panels. Special flashings designed to work as a system are used to finish off the roof. The exposed ends of the roof at the eaves are covered with eave flashing. They can also be left unflashed, especially if gutters will be installed. Rakes are covered with edge flashing; peaks are covered with hip or ridge cap. Roof penetrations must be properly flashed and sealed, and plenty of screws used to keep the flashing flat.
Installing tile roofing
Clay tile roofing is best suited for roofs that are greater than 20 degrees. As the slope increases, the aesthetics of the tiles become more defined, making them ideal for steep, cathedral-type roofs. Because clay tiles are so heavy, it is necessary to use 3/4" sheathing instead of 1/2" to be sturdy enough to carry the weight. It is installed the same way as all other plywood decking. The flashing that is used, as well as the waterproofing underlayment, fasteners, and attachment method will depend on the type of tile and the tile manufacturer’s instructions. The most common types of clay tiles are small, plain rectangles with a smooth or sanded surface; slate which comes in small rectangle sections of various sizes and thicknesses; pantiles with the distinctive “S”-shaped profile; and Roman tiles which are similar to pantiles but with a cross-section that is flat with a small roll.
Because clay tile roofing is susceptible to cracking, it often installed after any siding, stonework, stucco, and painting is done. This will minimize the need for walking on the roof and potentially cracking some of the tiles.
Prior to installing the roofing tiles all penetrations should have already been run through the roof with the proper flashing and roof jacks installed. Specialty flashings designed specifically for clay tile systems are used. Some flashings are installed before the underlayment, others after. Metal flashings are typically 28-gauge galvanized material, but other types such as rubber- or silicone-based flashings may be called for. Perimeter flashings are usually installed first. After the waterproofing layer, flashing around chimneys, conduits, vents, and roof-wall unions are installed. Types of underlayment that is used for tile roofs may range from ordinary tar paper all the way up to hot asphalt being painted over the plywood.
The old-fashioned method for tile installation is to nail each tile directly into the substrate and seal adjoining tiles with mortar. Tiles are laid in place starting from the eave edge and working in courses up toward the ridge in a cascading, waterfall format. Nailing holes are precast into the tile. Two 8d or 10d corrosion-resistant nails are hammered through each tile into the sheathing. Small pieces and cutoffs may need to have holes drilled in them for attachment. Cuts are made with a circular saw fitted with a masonry blade. Tiles are overlapped on the sides as well as between courses and concrete mortar is applied at the overlaps. Mortar is also packed into all areas where water could intrude. Ridge tiles are laid from each end toward the middle with mortar in between each overlapping piece. Two tiles are stacked at each end to begin the runs. A key tile is mortared into place over the last two tiles where they meet in the center of the ridge.
In recent years, other types of tile installation systems have become popular. The use of batten boards often replaces the need for mortar. Batten boards are typically wooden 1x3s or 1x4s, but they can also be made out of metal or plastic. The boards are nailed down to the substrate following the layout recommended by the tile manufacturer. Other systems may involve the use of interlocking tiles, built-in lugs, metal clips, wires, ballast stones, or proprietary fasteners. With all systems, however, it is imperative that tiles be installed loosely. Nails that have been driven too securely and over-tightened wires are likely to break the tile. Some building codes allow for tiles to be loose-laid on slopes less than 5:12. Tiles within 36” of a ridge, hip, eave, or rake require one nail to hold them in place. Loose-laid clay roofing is not allowed, however, in areas with snow or high winds.
PLUMBING
TO break plumbing down into its most basic concept, it employs the principle of “water in, water out.” So the purpose of plumbing a house is to bring water into the house so it can be used for a number of purposes and then be evacuated from the house when finished. Modern-day systems and fixtures make it possible for this process to be carried out in ways that are both sanitary and economical. There are three components to a working system: water supply, drainage, and fixture set.
If the home is being built on a slab-on-grade foundation, the sewage evacuation system is stubbed out before the concrete is poured. Any extensions of the water service provider’s supply line that will protrude through the slab are made at this time. This is all part of the preliminary plumbing phase of what is called the “rough-in.” After this stage is completed, an inspection is generally called for the sub-slab rough-in inspection. The concrete is poured after that inspection is passed. The bulk of the plumbing such as installing the home’s supply lines, drains, and vents, also part of the “rough-in” stage, takes place after framing but before drywall. Fixture installation is one of the final processes, being done during the FINISH WORK phase.
Installing water supply lines
Like the rest of the plumbing system, water supply piping follows the layout specified in the architectural drawings. Water is brought in from the street or from a well at about 50-60 psi through one main line that enters the house below the frost line. It connects to a shut-off valve usually located in the mechanical room or heater closet.* From there it is divided into two branches. One carries the cold water to the various fixtures throughout the house; the other connects to the water heater, after which the heated water is carried to most or all of those same fixtures. Traditionally, water supply lines are made of 1/2" or 3/4" copper tubing that is soldered together at the joints. Since water supply lines are pressurized, they can run in any direction; gravity is not a factor.
Supply lines are roughed in by boring holes in the wooden framing members, both walls and floors, slightly larger than the pipes going through them. After all the piping has been run, the plumber goes back and solders all the joints. Where pipes that will supply sinks exit the walls, copper fittings called “stub-outs” are soldered to a copper “hold-rite” bracket specially designed for the purpose. Stub-outs are short pieces of copper tubing with one closed, bullet-shaped end. Alternately, pieces of regular copper piping may be used with a cap soldered on to the end. Where the water supply will terminate at a tub or shower, the copper lines are soldered to a mixing valve which regulates the flow of water into those fixtures. Washing machine supply lines often terminate in an outlet box that is recessed into the wall, making shut-off valves for the machine easily accessible. Supply lines for toilets also employ stub-outs; they will be fitted with a separate shut-off valve during the FINISH WORK phase. Because modern tubs and showers are quite large and unwieldy, it is a common practice to set them as part of the rough-in, either just before or just after framing. They are often placed in the bathroom areas even before framing begins.
* Pex plumbing employs a manifold system which makes it possible for the water to each room or fixture to be shut off individually (see Installing a Pex system).
When water will be used for irrigation, the supply lines are often separate from house water lines. Sometimes they are even connected to their own meter. These lines typically terminate in stub-outs on the outside walls where hose bibs and/or sprinkler manifolds will be located. If the home will be serviced with gas, the main gas line is run in from the street and terminated where the gas meter will be installed. The piping for the house may also be run at this time. Usually, the utilities company will set the meter and everything can be hooked up after that. Gas lines are heavy-duty galvanized steel pipes, the ends of which are threaded on site and connected using galvanized fittings. Natural gas may be supplied to a furnace, fireplace, range, dryer, outdoor barbecue, or other appliances. Final connections are made during the FINISH WORK phase.
Installing drains and vents
The purpose of drain pipes is to carry water from sinks, tubs, and showers out of the house. Waste pipes refer to those drain pipes which carry sewage out from the toilets. Vent pipes evacuate noxious sewer gases out of the house and allow air to move freely in all the other pipes, thus preventing backups and gurgling.
Drain, waste, and vent pipes are generally made out of the same material and they work together as a system, so they are installed at the same time. In fact, most homes nowadays are serviced with what is called a “Drain-Waste-Vent” (DWV) system. This consists of pipes all made out of the same material but varying in size, depending on the purpose. Every house has one or more “soil stacks,” that is, a 4” vertical pipe running from underneath the house where it connects to the sewer all the way through the house and out the roof. Other pipes feed into the soil stack. Pipes are sized as cost-effectively as possible and still able to minimize the occurrence of blockages. Showers usually use 2” pipes; bathtubs, sinks, and service tubs are typically served by 1-1/4” to 2” pipes, depending on the intended usage and expected flow load.
DWV piping forms a network of lines that run throughout the house and are connected with fittings of the same material and glued together using solvent cement specifically formulated for the type of pipe being used. DWV systems come in three different types of plastic for residential construction: polymerized vinyl chloride (PVC), chlorinated PVC (CPVC), and acrylonitrile butadiene styrene (ABS). ABS is the simplest of the three to use and it doesn’t need to be primed prior to being cemented.
One of the most important factors to consider in planning and installing rough-in plumbing is what is called “fall.” Fall refers to the slope of a drain pipe. If a pipe does not have enough fall, it will drain too slowly; too much and it will leave waste behind. So the standard formula that covers both issues is 1/4" of fall for each horizontal running foot of drain. This can vary, depending on the size of the pipe. Larger pipes, for instance, usually require less fall.
Proper venting is essential for a plumbing system to work correctly. The water that runs through drain pipes must have a constant source of air to flow smoothly. Without venting, water flow would be severely restricted. Without the proper amount of venting, pipes and faucets would gurgle and water would flow inconsistently. All drain pipes are connected directly to a vent pipe, often being part of one integral run straight up through the house and out the roof. In order to cut down on the number of vents protruding through the roof, several can be terminated into a single vent before exiting the roof, that often times being the main DWV soil stack. If a vent is located too far away, usually over 10 feet from the main stack, it must pass through the roof separately. Fall is also a factor in vent pipes that run horizontally. Most codes require that DWV system be “washed,” that is, it must have enough fall to prevent moisture accumulation anywhere in the system.
In order to prevent sewer gasses from backing up into the house, traps are one final piece of plumbing that are installed wherever a drain pipe connects to sources of waste water that are open to living space such as faucets, sinks, and showers. A trap is a U- or S-shaped piece of pipe of the same material as the rest of the connecting system. Traps are an ingenious piece of technology: the simplest of valves with no moving parts. They are designed to hold a small amount of water that acts as a plug when water is not flowing, holding noxious gasses at bay. When the fixture is turned on, that bit of water is replaced with different water that remains when the fixture is turned off. Thus it is a valve that is both never open and never closed. P-traps connect to fixtures that drain through the wall; S-traps are used when they drain through the floor.
Plumbing systems are typically roughed-in after the house is framed but before the roof sheathing is installed. This is to make it possible for the roofer to cut holes in the sheathing exactly where the vent pipes are located rather than having the plumber cut holes afterward to run vents through the roof. On many custom homes, as much venting as possible is run through the back side of the roof in order to minimize the number of penetrations breaking up the roofline from the front view.
Installing a Pex system
Pex is an alternative to copper for running water supply lines throughout a building. Although relatively new in this country, Pex has been used successfully in Europe for decades. Unlike traditional plumbing tubing, Pex is not metal but plastic. “Pex” is an acronym for cross-linked polyethylene. Its advantages over copper are considerable. It is less expensive, costing about one-third of the price of copper; it is faster to install; it doesn’t corrode like copper in areas with acidic water; and it is highly resistant to bursting in areas of extreme cold. In addition, using Pex’s manifold system, separate shut-offs can be installed for each fixture at a central location. Given time, Pex will likely become the ad hoc standard for residential plumbing applications.
Pex systems consist of plastic tubing in a number of different sizes, proprietary fittings for various applications, and several different attachment options. Pex installation requires special tools created specifically for the job including tubing cutters, crimpers, and ring removers. These tools add to the initial investment, but once purchased will pay for themselves quickly over the course of time and with regular use. Although simple enough for a do-it-yourselfer to use, this initial investment may make Pex installation cost-prohibitive if the tools will only be used on a single build.
The same general installation principles are used with pex as they are with any other type of material. The blueprints will indicate the layout design specified for each project. Although it can be set up like a conventional trunk-and-branch system, much of the advantage of using Pex would be lost by doing so. The manifold system, also known as the “home run” system makes the cost-effective use of that advantage. It employs a single manifold installed in a mechanical or utility room which has shut-offs for each fixture in the kitchen, laundry room, and bathrooms. A third option that is sometimes used to conserve hot water is the submanifold system in which a separate smaller manifold is installed to service each room. Because it is the most commonly used, this handbook will cover installation of the standard single manifold system.
The first step is to drill holes through the sill plates and studs wherever the tubing will be run. Different fixtures require different sizes of tubing; it is necessary to make sure that each hole is slightly larger than the pipe that will be going through it in order to allow for expansion and contraction. Holes should be drilled in the center of each stud to avoid being penetrated by screws during the drywall stage. Some plumbers like to use nail plates as an extra precaution.
Once all the holes are drilled, the supply lines can be pulled through them and secured. Since Pex is not only flexible but also comes in rolls, long runs of tubing can be run without having to install joints every 10 feet. The tubing is secured using special clamps which are nailed into framing members. The blueprints will specify where and how often clamps are to be placed. Once secured, the tubing should have some slack between anchors and will still need to be able to slide freely because, being a plastic, Pex is subject to considerable expansion and contraction as weather changes. As an added precaution, an expansion loop is often installed in long runs. Blue Pex tubing is generally used for cold water supply lines while red is used for hot water. Some plumbers use all white Pex. As the tubing is being installed, the plumber will cut the pieces with a special pair of pliers designed to give the tubing straight, burr-free ends, essential for proper installations. It is also a good practice to label both ends of each line to avoid misconnections.
Where lines terminate in a room, special fittings are used. These consist of copper flanges into which angled copper stub-outs with a Pex adapter on one end are soldered. An alternative method for handling stub-outs that will be concealed out of view is to run the Pex all the way out the wall and attach it to a special fitting called a drop-ear bend support. If the termination point will be a shower, copper Pex adapters are soldered to the mixing valve. All plastic pieces must be removed from the mixing valve prior to soldering to avoid their being damaged by the heat. When the valve cools sufficiently, it can be reassembled.
Supply lines are now attached to all the fittings with a crimping tool and special rings.* There are three basic types of attachment rings available, each with its own crimping tool. They are the copper crimp ring, the stainless steel pinch clamp, and the stainless steel crimp sleeve.# Of the three, the pinch clamp is the one used mostly by DIYers because of its familiar crimping method. The crimp ring is employed most often by professional plumbers. To make the attachment, a ring is slipped over the end of the Pex and then the tube is pushed onto the copper fitting. It is absolutely essential that a space between the tube and the shoulder of the fitting is no less than 1/8” and no more than 1/4". This will allow for expansion and contraction and still ensure a secure connection.
* Pex can also be connected with specialized fittings called “push-to-connect” or “stab-in” fittings (such as SharkBite?) that do not require any special tools. They are designed to be simply pushed on to the pipe to create a watertight seal. Some codes do not allow the use of push-to-connect fittings for underground or behind-the-wall installations.
# Another type of Pex connection system that uses Uponor products is discussed below.
The ring is then crimped with the proprietary tool. After each crimp, the ring is checked with a special tool called a “go-no-go gauge.” This simple gauge is slipped onto the ring. If the crimp is correct, the ring will stop just short of bottom of the slot in the gauge. If the crimp is too tight, it will slip to the bottom of the slot; if it is too loose, it will not fit in the slot at all. In either case, the ring must be removed and the connection recrimped. Special tools are made for that purpose. In some cases, a Dremel tool fitted with a cut-off wheel can be used.
The next step is manifold installation. The manifold is designed with two large inlet fittings for the cold and hot water supplies and several smaller fittings for each of the fixtures it will serve. The more fixtures, the larger the manifold. A template is used to mark points on two studs where the outgoing tubing will run. Generally speaking, the cold water pipes attach to one side of the manifold; the hot water pipes to the other.* After the holes are drilled, the manifold is positioned between those studs and in line with those holes. Brackets attached to the manifold on top and bottom span the studs. They are screwed in place to secure the manifold. A shut-off valve is screwed onto each one of the incoming water fittings, with all the levers facing the same way.
All the tubing is then attached to the manifold, using the same crimping method as with all the other connections. A length of Pex is attached to the cold water supply where it enters the house and the other end is crimped onto the main copper cold water tube in the manifold. The hot water supply, whether Pex or copper is attached to the water heater and another piece from the water heater to the copper hot water tube in the manifold. Pex cannot be located closer than 18” from the water heater, so a length of copper is attached to the water heater first and then the Pex is run from there. Finally, tubing supplying the house is crimped to each of the shut-off valves on the manifold. The system is pressurized and checked for leaks. One of the inherent advantages to Pex systems is that a leak in one line does not require the entire system to be shut off to fix; only the valve feeding that line need be closed.
Uponor systems
Uponor Corporation is a Helsinki, Finland-based company that was founded in 1918. Its products have been used in the US for radiant heating systems since the 1980s. Uponor was the first to introduce tubular expansion technology to America.
The Uponor system uses the highest grade of Pex available called Pex-a along with special sleeves and an expander tool to make watertight plumbing connections in residential properties. Pex-a is the most flexible of all Pex types. Because of its shape and thermal memory, it can use ProPEX? expansion fittings, specially designed for use in this system. One of the unique characteristics of these fittings is that they get stronger over time, making them highly resistant to leaking.
* In some cases, the manifold is attached to a backboard and can be positioned vertically or horizontally. All the tubing may also exit the manifold in the same direction with each cold and hot water tube running side-by-side.
The ProPEX? expansion sleeves come in all the standard plumbing sizes, as does the Pex-a tubing. These fittings accomplish the same purpose as do the crimp rings discussed above in the Installing a Pex system section. The difference is that this system uses expansion and contraction to create the seal. Each sleeve looks like a small piece of tubular plastic and is approximately the same size as the fitting that will be inserted into the tube to make the connection. The sleeve is placed over the end of the tubing and pushed down until it is stopped by a small lip on one end of the sleeve. Then the tubing is placed over the end of a special powered expansion tool made by Milwaukee. Using oscillating and turning actions, the tool expands the tubing and sleeve a little at a time as the worker applies force to push the tubing in toward the hilt of the tool. When the expansion is complete, the tube is removed and the appropriate fitting is immediately placed into the tube. Withn about 20 seconds, the tube and sleeve return to their original size, making a watertight seal around the fitting. The rest of the installation is done the same as with the other Pex installation methods.
ELECTRICAL
WHILE electricity is the single most important source of modern lifestyle convenience, it also presents the highest risk of death and devastation from hazards such as fire and shock. For this reason, today’s new home wiring installation projects adhere strictly to electrical safety standards and national as well as local building codes. In some urban areas, a homeowner is not allowed to wire his own house unless he has an electrician’s license. In other areas, he may do so if he is under the supervision of a licensed electrician. Rural locations often have much more relaxed guidelines. However, all electrical work, regardless of locality, must be done according to the regulations of the municipality in which the home is located (including being legally permitted), and it must be inspected and approved by that authority to ensure that it is all code-compliant.
Similar to plumbing, the electrical phase is made up of three main sub-phases: service installation, wiring rough-in, and fixture installation. The first two can usually be done consecutively (doing the wiring immediately after the service has been installed) or even concurrently (installing wiring and service at the same time), with final connections being made once both are complete.
Installing the service
The company that provides electricity to your home will install a meter on the house and connect their power to it. The box that houses the meter will then be connected to a breaker panel located behind, adjacent to, or in the same area as the meter box. It will provide the amperage sufficient to run all the electrical fixtures and appliances in the home. That chain of electrical power, from the street to the meter to the panel, is called the “service.” The power company, being the service provider, will ensure this chain is properly installed as part of the service that they provide. From the service panel on, all electrical connections and fixtures become the responsibility of the electrical installer and the general contractor or homeowner.
To determine the size (in amperage) that the service to a house will require, a service load calculator is used to estimate the amount of power that each room will use individually. That will include the furnace, air conditioner, washer and dryer, all other electrical fixtures and appliances, and all lighting and outlets. These numbers are all added together and then demand factors are applied. The result is a number that the amperage service will be based on. Virtually all small- to medium-sized homes these days employ a 200-amp service. The next step up is a 320-amp service. However, this size of service is most often used in unusually large homes or homes with equipment that place an extraordinary demand on the power resources. A 200-amp service is generally enough for a typical home these days.
Depending on a number of factors, the service will enter the house in one of two ways: underground or overhead. All things being equal, the underground method is preferable as it reduces the chances of damage caused by inclement weather, careless drivers, etc. Reduction in the amount of overhead wires is also more aesthetically pleasing. The electrical contractor is the one who typically will install a blank meter box on the house and connect it to the service panel. With an overhead service, he will then run a piece of exterior conduit (called a “riser”) up from the meter box and through the roof, and at least two feet above the roof’s surface. A roof jack will be slid over the conduit and affixed to the roof decking. A weatherhead is attached to the top of the conduit to protect the electrical connections. The service provider will then run their main cable from the power pole over to the connecting point under the weatherhead on the roof.
Underground service requires that a trench be dug between the power pole or power hub and the house, terminating just under the location of the meter box. Special gray conduit designed for underground use is placed in the trench and the cable is run from the power source to the meter box. Sometimes an inspection of the finished work is required by the governing authority before the trench can be backfilled, but often the power company is allowed to do its own inspection.
Then the power company will install the actual meter in the meter box and make their final connections. Once this is all approved, electrical power is now available to the house and can be used as needed and turned off when not needed.
The two most common ways to connect the meter box to the service panel is either directly, back-to-back, or in adjacent wall cavities. The meter box is mounted on the exterior of the building while the service panel is mounted on the interior. A practical location is determined for the installation of these two boxes, always on an outside wall and often in a garage or utility room. Some home layouts make it necessary to locate the service boxes in an occupied room such as a bedroom or closet. Both the meter box and the service panel may be mounted on the surface of the wall or set into the wall (flush mounted) so that only the covers of the boxes are visible. Again, aesthetics plays an important part in making this determination.
If the meter box is installed back-to-back with the service panel, a simple piece of conduit called a “nipple” is used to make the connection, providing a passageway for the wires to be run between the boxes. If the boxes are located in adjacent stud spaces, a special cable called “SER” (service entrance round cable) is run from one box to the other. In either layout, the service disconnect (main breaker) is located in the service panel. However, if for some reason the panel must be located some distance away from the meter box such as across the room, the panel box becomes a “sub-panel” and the service disconnect stays with the meter box. Though now a sub-panel, this is still the main breaker box, also referred to as the “main lug.”
At times, other sub-panels may be employed in a home’s layout. For example, if a well pump is located some distance away from the house, a 60-amp sub-panel servicing only the pump may be placed in the well house. That way, electricity may be disconnected from the pump for servicing without having to do so at the home’s main breaker box.
There is no minimum height requirement for the location of these boxes. However, they typically cannot exceed a 6’-6” maximum height to the center of the meter globe. Most installers make this placement at 6’ simply for convenience. Many times, the height of the two boxes relative to each other is determined by the location of the wiring access holes (called “knock-outs”) in each box. Again, location is often based on convenient access. Legal clearances from walls and in front of the panels are also spelled out in the electrical code for the area.
Inside the panel box itself is a large non-metallic “panel,” two large terminals called “lugs,” and two metal “bus bars” with a number of set screws in them where house wires will be connected. The main power lines from the service provider (called “feeder conductors”) will be brought into the panel. If this is a back-to-back mount, these lines will be fed through the connection nipple from the meter box. If this is a side-by-side or sub-panel layout, the feeder conductors will be encased in the SER cable which will be run from the meter box to the panel through a large knock-out, usually located on the top or on one side near the top. The sheathing is stripped off the cable up to where about ?” of sheathing remains visible inside the panel box.
The wires that are exposed by stripping off the sheathing are two very heavy-duty line wires and a neutral wire. The line wires are either 2/0 copper or 4/0 aluminum. The neutral is either #1 copper or 2/0 aluminum. About a ?” of the insulation is stripped off the neutral wire (which is usually bare, white, or white-striped) and it is secured to the ground/neutral bar with a set screw. Next, about ?” of insulation is removed from the line wires (usually black, but can be any color but green or white) and each of them is inserted into a lug on the main breaker and tightened with the set screw. If the wires are aluminum, some anti-oxidation compound is applied to the ends prior to installation.
The entire service chain is now complete. After the house wiring has been run, the main line from each circuit (called the “home run”) will terminate in this panel box and be connected to an appropriate breaker which will protect that circuit. As mentioned previously, oftentimes the house wiring is done simultaneously with the service installation and the circuits are connected at this time as well.
Installing the ground
Although not technically part of the “service,” as it can be installed at any time during the electrical phase, the grounding system is an absolutely essential part of the service and is best planned and executed early on. The grounding system provides a path for electricity to go back to the earth, or “ground.” In case of an electrical fault or short, the electricity in an ungrounded fixture or appliance will try to find its own ground. Since a human being also makes a good ground, this could lead to electrical shock or even electrocution. Grounding provides another path for that errant electricity to go, thereby protecting someone who may inadvertently come into contact with an electrical fault.
This safety measure is accomplished by driving metal rods into the earth and connecting them to the service panel. There are dedicated grounding rods made of copper alloy and pointed on one end to facilitate easy entrance into the ground. In many construction projects nowadays, a simple piece of rebar is use to accomplish the same thing. This piece of rebar installed prior to pouring the concrete and is called a “concrete-encased electrode,” or more commonly a “ufer” ground. It is driven into the ground and stubbed up near the service location. It is held in place when the concrete is poured. Most local codes require that two 8’ long grounds, whether ufers or regular copper rods, be driven into the earth at least 6’ apart. These are connected together with a continuous piece of #4 copper wire that runs between them and all the way back to the service panel. The connection is made to the exposed end of the rod (called a “grounding electrode”) with an acorn clamp in the case of grounding rod or a two-piece clamp when using a ufer. Access must always be maintained to the electrodes, so if a ufer is located inside of the structure itself, a mud ring or some other type of access panel is installed prior to any final finishes being applied.
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