Is Fiberglass Or Foam Board Insulation Better For Your Crawl Space?

4 April 2022
 Categories: Construction & Contractors, Blog

Two traditional options for insulating a crawl space are loose fiberglass batts and foam boards. These options have their advantages and disadvantages, and they're each worth considering depending on your specific budget, climate, and needs. Since choosing the best insulation can have many long-term impacts on your home, it's worth carefully deciding between these options.

Why Should (Or Shouldn't) You Choose Fiberglass Batts?

Fiberglass batts are the typical loose insulation you see in many homes. These products come in large sheets that you can easily fit between the floor joists above your crawl space. Installing fiberglass batts is straightforward since these insulation sheets simply slot into position and remain in place from the tension between the joists.

Fiberglass batts come in varying thicknesses to provide an appropriate R-value for your home. Note that the correct R-value will depend heavily on your local climate. Warm areas typically require lower R-value insulation, especially below floors, while colder climates require a higher R-value. You'll want to choose the correct insulation level to meet local codes and maintain comfort in your home.

Fiberglass batts are cheap, easy to find, and relatively quick to install. However, they have a few downsides. These batts are not moisture tolerant, making them unsuitable for unsealed crawl spaces. Likewise, they may not work well if you have frequent pest problems. Rodents sometimes use fiberglass for nesting, so you may want to consider other options if you have pest issues in your crawl space.

Why Should (Or Shouldn't) You Choose Foam Board Insulation?

Unlike fiberglass batts, foam board panels install on your crawl space walls. These panels typically consist of a few inches of foam with a specialized reflective lining on the inner surface. Installers place foam board on walls using special fasteners driven into the foundation, creating a stable and permanent installation.

Foam board has several advantages. These panels can provide similar R-values to batts placed in the ceiling joists, but they leave the ceiling exposed and accessible. This access can be valuable if you have plumbing, HVAC ductwork, or other utility items in your crawl space ceiling. There's no need to remove foam board panels for plumbing or HVAC work.

Foam board is also more moisture resistant and doesn't have potential pest issues like fiberglass batts. However, these panels can be more expensive to purchase and install. This higher price may be worth considering if your crawl space has significant moisture issues or you're concerned about the possibility of pests making a home in your fiberglass insulation.

Ultimately, there's no single correct answer for every crawl space. The best way to choose appropriate insulation for your home is to discuss your budget and needs with an experienced installer.

For more information on crawl space insulation, contact a contractor in your area.