Spray foam insulation is made up of 2 chemical compounds, which expand when combined and then simultaneously seal and insulate the area. Spray foam insulation is the most efficient, but it can be up to 2-3 times more costly than other options. Spray foam is the best insulation material for your crawlspace or attic. It has a higher R-value, mold resistance, moisture damage resistance, durability, air sealing, versatility, and cost. The advantages of spray foam Best R-value per inch. It is very effective at stopping air leaks and providing insulation value. It won’t shrink, lose its value or fall out of position. Closed-cell spray foam can be waterproof and won’t support mold growth The disadvantages of spray foam Fiberglass is 2-3 times more expensive than fiberglass, for the same R-value. If the materials are not properly installed and the chemicals are not mixed equally, the material may not cure. This means that you won’t be able to stay in your house until it has been treated. During installation, you cannot be at home. High risk of damage – Every drip of foam material is irreversible, as the foam is similar to glue.