Foam Board Insulation

Rigid foam board insulation is an excellent alternative to fiberglass batt insulation. It offers higher R-Values per inch of thickness and is moisture resistant.

Foam boards are typically installed in between studs and joists. They can be cut to perfectly fit your home, making them an easy do-it-yourself project.

Easy to Install

Foam board insulation is easy to install, even for DIYers. However, before attempting this type of project at home, it’s important to recognize your limits and consult a professional. Foam insulation is flammable and should be sealed with a layer of drywall once it’s installed.

The first step in installing foam insulation is to measure the height and width of the area you intend to insulate. This will help you determine how much of each type and thickness of insulation you need.

Once you have the right amount of insulation, mount it between studs. You can use button cap nails to do this, but make sure the nails are driven into each stud so that they penetrate at least 3/4 of an inch into the wood behind. This will help prevent the insulation from being pulled out over time. Foam boards can also be nailed to the frame of an existing wall using screws with large washers, and adhesive designed specifically for this purpose.


Foam board insulation is extremely durable and can be used in a variety of ways in your home or business. It is often installed in areas of your house that are exposed to the elements such as rim joists, drywall and exposed basement walls. It is also commonly installed in attics and crawl spaces.

There are many types of foam board insulation on the market, some with higher R-values than others. The R-value of a type of foam insulation is determined by thickness, density and material type.

Expanded polystyrene (EPS) is the most recognizable form of rigid foam board insulation. It is made from materials that are water-resistant and flame retardant, protecting it from damage if exposed to moisture or open flames. It offers a R-value of about 4.6 per inch of thickness. Extruded polystyrene rigid foam insulation, known as XPS is typically blue and pink in color. It is manufactured by companies such as Pactiv, Owens Corning and Johns Manville. It is more expensive than EPS but offers higher R-values and has a lower permeance. It uses less petrochemically-derived blowing agents than EPS but it still has a high embodied energy.


Foam insulation boards are a great solution for those looking to upgrade the insulation in their homes. They are affordable and cost less to install than fiberglass insulation. Foam insulation is available in a variety of thicknesses to meet your needs and budget.

Foam board insulation is a great choice for new construction and existing homes. It is durable, lightweight and has high R-values per inch. It is also moisture-resistant, making it ideal for exterior walls, basements and crawl spaces.

Expanded polystyrene (EPS) foam insulation, which is commonly found at home centres is the least expensive of all the rigid foam insulation types and carries an R-value of about 4. EPS is lightweight and easy to cut. It has a good compressive strength and unlike other types of insulation it does not lose its R-value over time.

Extruded polystyrene (XPS) is similar to EPS but has greater R-value per inch of thickness. XPS is stronger and much more resilient. It does have a higher embodied carbon than EPS but not as much as blown in fiberglass or spray foam insulation.


Foam board insulation is an excellent choice for areas where moisture resistance is a priority. This includes below grade insulation for slabs and walls in passive houses, as well as insulating foundations to curb thermal bridging and reduce the risk of moisture leaks.

Foam board insulators also act as vapor barriers or retarders in stud cavities. This keeps sheathing warm and dry and helps prevent mildew or mould from developing. The type of foam board insulation you choose depends on the climate and your energy goals. Different types have varying R-values and permeance ratings.

Expanded polystyrene (EPS) insulation is easy to cut and fits easily into a variety of spaces in your home. It is a good choice for below-grade insulation as it resists moisture, and it’s often used in wall sheathing under house wrap or on the exterior of a home. The downside is that EPS is not fire-resistant and can billow black smoke when exposed to flames. XPS and polyiso are both made with cross-linked polymers, so they are less susceptible to degradation but still not fire-resistant. Polyiso has the highest R-value of all rigid foam insulation, but it’s also the most expensive. Its blowing agents are HCFC-134a and HCFC-142b, which have a global warming potential up to 1430 times worse than carbon dioxide.