Spray foam insulation is quickly becoming the go-to option for insulating attics. It is far less messy than fiberglass insulation, and it will not make your skin itch or scratch your skin like fiberglass does. There are two types of spray foam insulation used for insulating attics, and each one has its own unique benefits.
Closed Cell Insulation
Closed cell insulation is called "closed cell" because the pockets in the sprayed foam are filled and not hollow. This provides a greater density in the final product, and a higher R-value, which is essential for conserving heat and energy consumption. Closed cell insulation is less effective at soundproofing, and more effective at keeping your home comfortable all year. It is very hard to crush closed cell insulation in your hand, which is how you can tell the difference between closed cell and open cell insulation.
Open Cell Insulation
Open cell insulation is so named for its hollow cells after the spray foam expands. It is not very good for keeping a home warm, which is why it is more commonly used in the southern half of the U.S. where heating is less important. The one thing that open cell insulation does best, however, is sound-proof your home. Sound waves are caught within the many hollow cells in the expanded foam, and then do not transfer through your walls (in or out!).
Combining Open & Closed Cell Spray Foam Insulation
If you want to keep your home warm and sound-proof it with spray foam insulation, there is a way you can do this. The open cell foam has to be sprayed on your attic walls and surfaces first, so that sounds from outside cannot travel inward. After that layer has successfully expanded and dried, then you spray the closed cell layer of foam insulation on next. Doing it in this order blocks heat from escaping your home and stops noise from inside your home from getting out. The sound can travel through the closed cell layer, but is blocked when it hits the open cell layer underneath.
Choosing What to Use & How to Use It
If you live in a region of the country that almost never dips below forty or fifty degrees, all you really need is the open cell insulation. The colder regions of the country definitely need the closed cell insulation. However, you could do both types, no matter where you live, if you wanted to. To have a better idea of which spray foam insulation you need, contact companies like Calhoun Insulation.