Fire and water pipes don’t mix

Wildfires can cause a great deal of property damage, and it seems as if they’re becoming more and more common in parts of North America. Of course, brushfires and forest fires are quite natural phenomena. They’re nature’s way of facilitating forest rejuvenation by burning off dead wood and brush and clearing the way for new growth. Part of the reason for the perceived increase in wildfires is the fact that residential and other developments are moving closer to land that was previously undeveloped. We build houses close to the forest, so when that forest catches fire, the homes are exposed to danger.

Together with residential and business development we create infrastructure, part of which are water and sewer pipes. Of course, these have to be run through developed areas, and when there’s a big fire close by, there’s a risk that underground pipes can be damaged. In some cases, the damage isn’t immediately apparent; for example, the heat can buckle some pipes so joints become insecure.

Earlier this year, the western region of the U.S. saw a series of winter storms with record-breaking rainfall. Once this massive infusion of rain abated, vegetation began to grow. A few months later, drought conditions struck the same region, and all that vegetation and brush has turned into fuel for wildfires.

At the time of this writing, there are at least three major wildfires raging through parts of Arizona, Utah and California. Together, the current burnt areas total around 140,000 acres of land. This is just what the U.S. Forest Service classifies as serious Type 1 Incidents. If you’re interested in checking out where there are large forest fires at any time, there’s a website that maps them here.

So, what happens when fire and water pipes mix? Of course, this depends on the depth of the pipe and the material they’re made of. If located fairly close to the surface, or where there’s an exposed pipe opening, most pipe materials run the risk of being damaged or even destroyed by fire. When specifying in areas where fires are a risk, this is something that must be taken into consideration. Large-diameter pipes need to be buried deep enough to avoid being exposed to extreme heat in the event of a big burn.

Fires in concrete generally don’t affect structural strength, flow capacity or corrosion and abrasion resistance. However, damage can occur with other materials, such as polyethylene pipe (HDPE) or polypropylene (PP). If you want an instructive lesson in what can happen when polyethylene pipe meets fire, you can check out the story of a fire at an Ohio company that makes drainage pipes. The fire, in which (luckily) no one was injured, resulted in, “… one big glob of plastic … probably an acre-and-a-half of burnt plastic.”

It almost goes without saying that large fires can cause massive damage and incur costs. The repair or replacement of infrastructure is incredibly expensive, and there are social ramifications, such as the interruption of service and the disruption of traffic if the damaged line runs near a road. Pipe culvert failure can block emergency service vehicle access, and this can result in the loss of property or, even worse, lives.

In addition to naturally occurring fires, the sad truth is that fires in drainage pipes are not uncommon. The American Concrete Pipe Association has dozens of articles and sources reviewing the danger and effect of fire in drainage systems.  

Fires in drainage pipes are more common than many people think. For this reason, systems should be designed with this in mind. Plastic burns, and so there’s always a risk of pipe damage. However, because of the relative volatility of HDPE pipe, damage can occur beyond the pipe itself. In one case reported near Tuscon, Arizona, some children were playing with fire in an HDPE pipe, which ignited. The pipe itself, the sidewalk, roadway and surrounding structures were damaged, and the blaze came dangerously close to a large gas main. In this instance, disaster was averted, but the proximity of burning plastic to a gas main could have had deadly consequences. If concrete pipe had been used instead of HDPE, there would have been no question of damage to the infrastructure, or risk of a lethal explosion. So why use plastic in the first place?

Thompson Pipe Group has been specializing in concrete pipe for decades. We’re always available to help you when it comes to selecting the best material or combination of materials for your next job. We have the products, engineering know-how and field support to ensure correct specifications and successful installations. Visit our websites here and here to see our range of products.

We understand the challenges of specifying pipes with diameters from 12" up to 156" as well as monolithic precast box culverts for different applications and circumstances. We can help you select the pipe that will best withstand all the natural and manmade events that may reasonably occur.

Even though fire and water pipes may not mix very well, by choosing a robust concrete product with the correct joining methods, it’s possible to create the conditions where they can survive the ravages of a wildfire. So while it may be possible to fight fire with fire, when it comes to our water infrastructure, we can fight potential fire damage in the future with the right pipe product: concrete.