How do you compare the R-values of fiberglass and cellulose insulation?

1 What are R-values?

R-values are a measure of how well a material resists heat flow. The higher the R-value, the better the insulation. R-values depend on the type, thickness, and density of the material, as well as the temperature and humidity conditions. R-values are usually expressed per inch of thickness, so you can multiply the R-value by the thickness of the insulation to get the total R-value of the layer.

2 Fiberglass insulation

Fiberglass insulation is made of fine glass fibers that trap air and slow down heat transfer. Fiberglass insulation comes in batts, rolls, or loose-fill forms, and can be installed in walls, ceilings, floors, attics, and crawl spaces. Fiberglass insulation has an average R-value of 2.2 to 2.7 per inch, depending on the density and quality of the product. Fiberglass insulation is relatively inexpensive, easy to install, and fire-resistant, but it can also irritate the skin and lungs, lose effectiveness when wet, and have a high embodied energy.

3 Cellulose insulation

Cellulose insulation is made of recycled paper, wood, or plant fibers that are treated with chemicals to resist fire, mold, and pests. Cellulose insulation comes in loose-fill or spray-on forms, and can be blown or sprayed into walls, ceilings, floors, attics, and crawl spaces. Cellulose insulation has an average R-value of 3.2 to 3.8 per inch, depending on the density and quality of the product. Cellulose insulation is more eco-friendly, more effective at blocking air leaks, and more resistant to moisture and sound, but it can also be more expensive, harder to install, and prone to settling and sagging.

6 Tips for improving insulation

No matter what type of insulation you choose, you can improve its performance and efficiency by following some simple tips. First, make sure that you have adequate insulation in all parts of your home, especially the attic, where most heat loss occurs. Second, check for any cracks, holes, or leaks in your walls, windows, doors, ducts, and pipes, and seal them with caulk, foam, or weatherstripping. Third, add extra insulation to areas that are exposed to cold air, such as rim joists, basement walls, and crawl spaces. Fourth, use curtains, blinds, or shades to block or reflect sunlight and heat in the summer and winter. Fifth, install a programmable thermostat to adjust the temperature according to your schedule and preferences.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?