Is foam board good for insulation?
Andrew Hansen
Published May 26, 2026
Foam board insulation is a great alternative to the very common fiberglass batt insulation that is in most of our homes. It has a higher R-Value per inch of thickness, it's resistant to moisture and is easy to work with.
Can foam board be used as insulation?
Foam board can be used to insulate any exposed cavity in your home from the top to the bottom, and even the walls if you are remodeling and the drywall is down.Which is better foam board or insulation?
Made from polymers like polyurethane and polystyrene, rigid foam boards are denser, more expensive, and offer better resistance to heat flow than fiberglass. Conversely, fiberglass insulation is cheaper and more flexible, as it is made from raw materials like limestone, silica sand, and recycled glass.Is foam sheet a good insulator?
Sheet foam provides better insulation and takes up less space than traditional fiberglass, and is much better at blocking air transfer when installed properly. The insulate properties of an inch thick foam sheet can be up to 3 times greater than other insulates of the same thickness.Does foam board have an R-value?
Foam board insulation R-value varies based on type but is anywhere from 3.6 per inch of insulation thickness to 8.0. The types of foam board insulation include polyurethane, polyisocyanurate, extruded polystyrene foam, and expanded polystyrene foam.Is foam board insulation flammable ?
Does foam board insulation need a vapor barrier?
Foam insulation usually does not require a vapor barrier. For some foam insulation types, such as closed-cell spray foam and foam board insulation, the insulation itself stops the movement of most water vapor.What is the R-value of rigid foam board?
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.Which foam board insulation is best?
Foam board made from polyisocyanurate (polyiso) generally offers the best insulation capacity and 6.5 per inch. Water is the primary "blowing agent," making it one of the most environmentally-friendly foams used.Is foam a good insulator for cold?
Generally all commercial coolers use the same method of insulation: foam between the inner and outer walls. Foam is a good insulator for two reasons.Is foam board insulation as good as fiberglass?
Foam board insulation is a great alternative to the very common fiberglass batt insulation that is in most of our homes. It has a higher R-Value per inch of thickness, it's resistant to moisture and is easy to work with.What is the best insulation for walls?
The best insulation for walls when it comes to new build homes or remodels is going to be Nu-Wool, foam board, or open cell spray foam.
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Cons:
- Open cell spray foam is an expensive option for insulation.
- Spray foam can't be installed as a DIY project.
- Some brands of spray foam have an odor when installed.