Once you understand the differences between 1-component and 2-component spray foam insulation, it is important to acknowledge a few factors that influence exactly how to implement it and how much to use.
Reading the codes
When you consider upgrading your building to spray foam insulation, one of the first things to take note of is the building code in your climate zone. These are regulations set forth by the federal government in order to ensure that buildings in different areas of the country are structurally sound and weather-resistant. Because the codes change every few years, it is important to double check before beginning construction.
Spray foam insulation can make a world of difference, especially in extreme climates. People living and working in areas where temperatures fluctuate greatly from winter to summer will spend more money on heating and cooling. Upgrading insulation can yield long-term savings and offer greater comfort.
Building codes will call for different minimum R-values for insulation depending on the region. An R-value is a unit of thermal resistance for a particular material or assembly of materials – in this case, insulation. The R-value depends on a solid material's resistance to conductive heat transfer.
Using infrared imaging
In order to determine which areas of the building are the most in need of insulation, infrared imaging is the best method. You may have a sense already, if there are particular rooms or areas that always seem to run cold. But by using a specialized infrared camera you can see in great detail what you may be unable to sense.
The camera can be used to picture the entire building from the outside, giving you a general sense of where to start. Then, in individual rooms, the imaging can reveal specific deficiencies, such as around wall studs, attics, roof slants – even poorly installed and ineffective fiberglass bats.
Blower door test
Another way to discover drafts in the building and places that should be sealed is through the use of a blower door test. The test uses a fan to pull air out of the building, lowering the pressure inside and drawing outside air in through cracks and leaks in the exterior.
Calibrated air blowers are ideal because the can measure the amount of air pulled out of the building, thereby determining how well the structure is sealed before and after spray foam application.
Before performing a blower door test, be sure to put out all fires, including coals, as the heightened air flow can stoke flames and become dangerous. Also check that all doors, windows and other outside access points are shut, while any cabinets, closets, or other built-in recesses are open.
Calculating the correct yield
Once you have identified the areas in need of spray foam insulation, you should make sure you know how to determine the amount of foam to use. One-component foam is measured in linear feet and will not expand dramatically, making it relatively simple to use. But for 2-component jobs, the product expands quickly and considerably, so it is essential you are aware of the way to measure it.
Two-component foam is measured in board feet. One board foot is equal to a square foot multiplied by the desired foam thickness. For example, a space that measures 10 feet by 12 feet equals 120 square feet. To insulate that space with 2 inches of foam, multiply 120 feet by 2 inches to yield 24 board feet of foam.