Foam board insulation is a type of insulation that is made from foam. It is used in various applications, including walls, ceilings, and floors. Foam board insulation has a high R-value, effectively insulating against heat loss. Foam board insulation is also resistant to mold and moisture, making it an ideal choice for areas susceptible to these problems.
Foam board is available in various thicknesses and sizes, making it perfect for multiple applications. The R-value of foam board insulation depends on the type, but it can be anywhere from 3.6 to 8.0 per inch of insulation thickness.
What is Foam Board Made of?
Most types of foam board insulations are made from polystyrene. Polystyrene is a plastic that is made from petroleum. It is a lightweight material made up of tiny cells of air. The cells are what give the foam board its insulation properties. Foam boards can also be made from polyurethane, another type of plastic.

Foam board insulation is a versatile and inexpensive way to insulate your home. It is easy to install and can be used in various applications. It has sound-insulating properties and can help to reduce noise pollution.
Types of Foam Board Insulations
There are three types of foam board insulation:
Extruded Polystyrene
Extruded polystyrene (XPS) is made of beads of styrene that are fused with heat and pressure. The beads are then expanded to create small voids throughout the material, which makes it strong and lightweight. This type of foam board is used for both exterior and interior walls, as well as ceilings.

These rigid foam panels often have smooth plastic surfaces and come in blue or pink colors. The R-value of Extruded polystyrene insulation is approximately R-5. This kind of rigid foam won’t absorb water and is more resilient than expanded polystyrene, making it the most adaptable sort of rigid foam. XPS insulation often has a white foil finish on the front and a foil vapor barrier on the back, giving the area exceptional insulation and a polished look.
Expanded Polystyrene
Expanded polystyrene (EPS) is a rigid, closed-cell insulation foam that looks similar to white plastic. It is produced in large sheets and cut into smaller pieces for insulation. EPS is also a very lightweight material, making it easy to transport and install. EPS is often used under the roof, over the walls of the foundation walls, and under the siding.
EPS is the least expensive and insulating type of rigid foam (around R-3.8 per inch). It also gets broken more quickly than other kinds of rigid foam. But EPS foam is a good addition for homeowners who want to save money and put it in places where it won’t get a lot of use. EPS is an effective insulation material because it has a very low thermal conductivity, meaning it does not conduct heat well.
Polyisocyanurate
Polyisocyanurate foam, also called “Polyiso,” is the rigid insulation with the highest R-value per inch (R-6.5 to R-6.8). This rigid foam insulation typically has a reflective foil facing on both sides, making it a radiant barrier. Although Polyiso boards are more expensive than other rigid foams, they offer the best results.
Rigid Fiberglass Boards
Rigid foam boards are one of the popular types of foam insulation, and they are made from glass fibers bonded together with resin. The rigid boards are then cut to size and used in various applications. Rid foam insulation also functions as an air barrier when the panels are sealed at joints and edges using tape and spray foam.
Rigid foam board insulation has a high R-value, which means they are very effective at insulating against heat loss. They are often used in walls, ceilings, and floors. Rigid insulation can also insulate electrical wiring (ductwork) and plumbing.
Why R-Value is Important with Foam Board Insulation?
When it comes to insulation, the R-value is important. This is a measure of how well the material can resist heat flow. The higher the R-value, the better the insulation. Foam board insulation has a high R-value, making it an effective way to keep your home warm in winter and cool in summer.

Foam board is also environmentally friendly, not containing harmful chemicals or VOCs. It has a high R-value, which effectively prevents heat loss. Foam board insulation is an excellent choice for both commercial and residential applications.
How to Calculate the R-value of Foam Board Insulation?
It’s essential to know how to calculate the R-value.
- First, you’ll need to measure the thickness of the foam board. This can be done with a ruler or a tape measure.
- Next, you’ll need to determine the density of the foam board insulation. This can be found on the product label/specification or manufacturer’s website.
Once you have these two numbers, you’ll need to multiply them to calculate the foam board’s R-value.
Is Foam Board a Good Insulation?
Foam board insulation is a versatile and inexpensive way to insulate your home. It is easy to install and can be used in various applications. It is an effective way to reduce energy costs and can also help to reduce noise pollution.

What are the Advantages of Foam Board Insulation?
There are many advantages to foam board insulation.
- Foam board insulation has a high R-value, which effectively insulates your home.
- Easy to install as it can be cut to fit any space and doesn’t require any special tools or equipment.
- Foam board is fire resistant and doesn’t off-gas or emit fumes like other insulation types.
What are the Disadvantages of Foam Board Insulation?
- Foam board insulation can be a little more expensive than other insulation options.
- It can be damaged easily if mishandled, so care must be taken when installing and handling it.
- It is not as effective at preventing moisture penetration as other types of insulation, so it may not be the best choice for areas prone to moisture damage.
Where can you Use Foam Board Insulation?
Foam board insulation is one of the most versatile types of insulation on the market. It can be used in various applications, both interior and exterior walls. It can also insulate electrical wiring (ductwork) and plumbing.
How thick your foam board insulation should depend on where in the home it is being installed, what climate zone you live in, and sometimes what kind of home heating you have.
- One of the most common uses for foam boards is to insulate basement walls. Basements are often cold and damp, making them difficult to heat and cool. It can help to keep your basement comfortable year-round.
- Foam board insulation can also be used to add insulation for attic insulation. Crawlspaces can be damp and musty, so insulating them with foam boards can help to keep them dry and mold-free.
How to Install Foam Boards?
Foam board insulation is easy to install. It can be cut to fit any space and doesn’t require special tools or training to install. It is also environmentally friendly, as it’s made from recycled materials.

- Measure the area you want to insulate and purchase the appropriate foam board insulation. Make sure to purchase enough insulation to cover the entire area you want to insulate.
- Cut the insulation to fit the size of the area you are insulating. Cutting it to measure can be difficult, so it’s best to purchase it in the correct size.
- When attaching the insulation to the wall or ceiling, peel and stick the foam board to a clean, dry surface.
- Tape all seams and joints for a watertight seal.
- To reduce exposure, dress in long sleeves, work gloves, protective eyewear, trousers, and a face mask.
- Make sure all gaps and cracks are correctly sealed to prevent heat loss.
What are the Alternatives to Foam Board Insulation?
There are a few other insulation alternatives, including:
Cellulose Insulation: made of recycled paper products, cellulose insulation is a good option for those looking for an environmentally-friendly choice. It is also effective in preventing heat loss. The average cellulose insulation R-value is ranging R-3.4 to R-3.8 per inch.
Fiberglass Insulation: made of tiny glass fibers mixed with resin and formed into batts or blankets. The glass fibers are fragile, which allows them to trap air and create an insulating layer. Fiberglass insulation may vary slightly by the manufacturer, but typically it has an R-value between 2.5 to 4.3 per inch.
Foam Insulation: spray foam application is sprayed onto surfaces and can be a good option for insulating tight spaces. It is also effective in preventing heat loss. There are two types of spray foam insulations.
- Open cell foam spray insulation comprises tiny cells filled with air. This type of insulation is less expensive than closed-cell spray foam insulation but less effective in preventing heat loss.
- Closed-cell spray insulation comprises tiny cells filled with gas twice as dense as air. This type of insulation is more expensive but more effective in preventing heat loss.