When it comes to insulation, the R-value of spray foam can vary depending on the product, manufacturer, and other factors. Open-cell spray foam insulation typically has an R-value of R-3, 6 to R-3.9 per inch, while closed-cell spray foam insulation has an R-value of R-6 to R-7 per inch. According to Green Building Advisor, closed-cell spray foam insulation provides an R-value of 6.5 per inch. This is significantly higher than other types of insulation such as cellulose and fiberglass, which only offer an R-value of 3.5 to 3.7 per inch. When deciding between open and closed-cell spray foam insulation, it's important to consider more than just the R-value.
Both walls are affected by the thermal reduction of heat loss through the wooden structure, but there are other factors to consider as well. Open-cell spray foam has an R-value of approximately R-3.7 per inch, while closed-cell spray foam has an R-value that can be as high as R-6.5 per inch. However, there are open-cell spray foam insulation products that actually offer R-3.7 per inch, such as the Icynene Classic and the Icynene Classic Max.The most important attribute of spray foam insulation is its ability to seal air by creating a customized airtight envelope within the building structure. This hermetic sealing of closed-cell spray foam reduces air leaks, moisture accumulation, and termite damage.
Closed-cell foam also increases the structural strength of a roof, wall, or roof due to its glue-like density and adhesion. If continuous rigid insulation with a high R-value is installed on the outer face of the cladding (for example, rigid foam or mineral wool), the entire R-value of the insulation contributes to the R-value of the entire wall (except in areas occupied by windows and doors). Low-density foams are called open-cell SPF, while higher-density foams are called closed-cell foams. Spray foam can easily double the potential insulating value of a wall where there are only a few centimeters of space available. Of course, this means that if used to make an unventilated, air-conditioned attic in a cold climate, contractors must cover the inside of the foam with a vapor retardant. In addition to its high R-value, closed cell spray foam also has a low conductivity gas in its cells and reduces air leaks more effectively than open cell spray foam. The main concern with closed cell spray foam is that most brands use an expanding agent that has a high global warming potential. If you're thinking about re-insulating your home, you have several options available to you.
Fiberglass insulation is one of the most common forms of home insulation and is very economical compared to spray foam insulation. Sometimes even homeowners can install it if they wish. The R-value of open cell spray foam ranges from R-3.5 to R-3.6 per inch, while closed cell spray foam ranges from 5.0 to 7.0 per inch. Ultimately, when deciding between open and closed cell spray foam insulation for your home or business, it's important to consider more than just the R value.
