Rigid Foam Insulation

Rigid Foam Insulation

Rigid foam is a durable, effective insulation material

Rigid insulation board

Your Dr. Energy Saver expert can help you choose the right type of rigid foam insulation for your needs.

When most people think of insulation, they think of fluffy materials that are easily compressed or torn. However, rigid foam board insulation is a unique insulation option that provides excellent durability and insulating capabilities.

Dr. Energy Saver provides quality rigid foam insulation for a variety of purposes, including basement, crawl space, and attic insulation. Our rigid foam options are proven to provide effective insulation and help make your home more comfortable and efficient.

If you're interested in rigid foam insulation for your home, call your local Dr. Energy Saver dealer today to get started with an estimate! Our rigid foam insulation will provide the solution you need for your home's energy loss problems!

What makes rigid foam insulation different

The key difference between rigid foam insulation and traditional insulation is, as you might expect, the strength of the material. Unlike batt and blown insulation, rigid foam won't blow or shift out of place once it's installed. It also is water and pest resistant, making it perfect for basements and crawl spaces.

Rigid foam insulation also offers benefits as air barrier, which can be accomplished when the boards are sealed at joints and edges with tape and spray foam. Rigid foam panels come in a variety of thicknesses and widths, but 2-ft. x 8-ft. and 4-ft. x 8-ft. panels are the most common. Rigid foam cuts easily with a knife or saw to fit unusually shaped areas, and it's typically cut to fit and wedged (friction-fit) into place. If needed, it can also be glued to surfaces with caulk, panel adhesive or spray foam.

Choose the right type of rigid foam for your needs

When choosing rigid foam insulation, you have three main options:

  • Polyisocyanurate: Known as polyiso for short, polyisocyanurate foam has the highest R-value per inch (R-6.5 to R-6.8) of any rigid insulation. This type of rigid foam usually comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier. Polyiso board is more expensive than other types of rigid foam, but it offers the most benefits. Our Foamax® polyiso insulation comes with a foil vapor barrier on the back and a white foil finish on the front, providing quality insulation while also adding a clean finished appearance to the space.
  • Extruded polystyrene: Extruded polystyrene (XPS) rigid foam is usually blue or pink in color, with a smooth plastic surface. XPS panels typically aren't faced with other material. The R-value is about R-5. Like polyiso, this type of rigid foam won't absorb water and is stronger and more durable than expanded polystyrene, so it's probably the most versatile type of rigid foam. XPS falls between polyiso and expanded polystyrene in price.
  • Expanded polystyrene: Expanded polystyrene (EPS) is the least-expensive type of rigid foam and has the lowest R-value (around R-3.8 per in.). It's also more easily damaged than the other types of rigid foam. However, EPS foam is a good addition for budget-conscious homeowners in areas where it won't be exposed to a lot of traffic.

Rigid Foam Insulation FAQs

What are the pros and cons of rigid foam insulation?

Benefits of rigid foam insulation include enhanced mosture control, continuous insulation, and its ability to address thermal bridging. Thermal bridging is when components of the home, such as metal or wood, allow heat to enter or escape the home due to their higher conductivity. Rigid foam insulation prevents this transfer and keeps the home at a stable temperature.

One of the only disadvantages of rigid foam insulation is that it must be tightly fitted in order to prevent air from escaping. This can easily be addressed with air sealing measures such as taping or adding blown-in insulation on top.

Can I spray foam insulation myself? How about rigid foam?

There are DIY foam insulation kits available at some hardware stores, but there are a lot of ways it can go wrong. Spray foam application must be done continuously or clogs will occur inside the canister, rendering the rest of the mixture useless. This makes it all too easy to waste expensive materials and valuable time. Spray foam is also incredibly hard to remove, as it sticks to every surface it touches. Experienced contractors will have the skills and precision to ensure that the spray only goes where intended.

Rigid foam insulation is easy to cut, but it takes skill to fit it exactly together. Homeowners who DIY rigid foam insulation installation will have to take extra steps to apply tape or other forms of air sealing to make the foam boards effective. Rigid foam insulation is also ideally applied during new constructions or inside of walls, which is best handled by professionals.

What is the R-value of a 2-inch foam board?

The R-value of rigid foam insulation varies based on the materials used and how many layers are installed. For example, our polyiso rigid foam boards have R-values between 6.5 and 6.8 per inch. If two layers are installed, it doubles the R-value and cuts heat/conditioned air loss in half. For reference, plywood has an R-value of 1.25.

How thick should foam board insulation be?

How thick your foam board insulation should be depends on where in the home it is being installed, what climate zone you live in, and sometimes what kind of home heating you have. For example, the minumum R-value for crawl space insulation across the U.S. is R-13. At Dr. Energy Saver headquarters in Connecticut, which is zone 5, the recommended rating for crawl space insulation is between R-25 and R-30 for both gas heating and electric heating set ups. If your rigid foam boards are rated R-6 per inch, you would need between 4.2" and 5" of insulation in your Connecticut crawl space.

Some areas of the home will require more insulation than others. For example, attics in zone 5 require more insulation than crawl spaces (R-49 to R-60 vs R-25 to R-30).

Check your local guidelines for the correct formula to determine how thick your rigid foam board insulation should be. Or, call the experts at Dr. Energy Saver for a free rigid foam insulation estimate and we'll determine what works best for your home.

What kind of rigid foam insulation is best?

The best kind of rigid foam insulation is polyisocyanurate, also known as polyiso. It has the highest R-rating of any rigid foam insulation and comes with a reflective foil on both sides, allowing it to act as a radiant barrier as well. This closed-cell rigid insulation can be used in a variety of applications, including cavity walls, stud walls, masonry walls and vaulted ceilings.

Dr. Energy Saver can provide expert rigid foam installation

If you need insulation for your basement, crawl space, or attic, rigid foam insulation is a good choice. Dr. Energy Saver can evaluate your home and recommend the right materials and services to give you the solutions you need. Call us today to get started on making your home more comfortable and efficient with an evaluation and estimate!

Find your local Dr. Energy Saver Contractor

Find Your Local Contractor


Areas Serviced

Find Local Dealer
Free Estimate