This is an alternative to traditional building insulation such as fiberglass. This is a two-component mixture that is composed of both polyol resin and isocyanate which both come together at the tip of a gun and form an expanding foam that can be sprayed on concrete slabs, through holes drilled into a cavity of a finished wall or on roof tiles.
Polyurethane is the most common type of spray foam insulation, which was developed as well as used in the 1940s and applied to airplanes. However it wasn’t until the 1970s that it was started to be used as a form of insulation. Various systems are used in order to spray this foam. The two-component high pressure system is used during new home construction because it is a quick expanding type of spray foam. The two component low pressure spray foam is another system that is used for remodel jobs where there are existing walls of drywall already there. This method is known as a slow rise formula.
Spray foam insulation can be categorized into two separate types: open and closed cell. The open cell foam insulation type is where tiny cells are not completely closed. It is less expensive because it uses fewer chemicals. It also has a good air barrier, but it does not offer a type of water vapor barrier. This type is more sponge like looking and is often used in interior walls to help with sound. It is not recommended for use in outdoor applications.
With closed cell foam insulation, the cells are more dense. This creates a smaller and more compact cell structure. This is great for air barriers and also provides a water vapor barrier as well. This type of insulation is often used in barrier projects and other outdoor applications, however it can also be used throughout the home.
Benefits of Using Spray Foam Insulation
This type of insulation helps to lower utility bills and to save on energy costs. The U.S. Department of Energy reports that 40% of a home’s energy is lose through air infiltration in the walls, doorways and windows. That means that buildings that are treated with spray foam insulation typically are insulated 50% better than those with traditional insulation products.
Insulation that is sprayed in buildings also helps to protect against moisture, which reduces the chance of mildew or mold in the home. By eliminating mold growth, you reduce the risk of rotting wood in a home as well as any allergic reactions to mold spores.
Spray foam insulation is also used in order to reduce noise. Foam insulation is great as a barrier for airborne sound transfer from a roof, floors and walls as well as a barrier to airborne sounds in general.
Also, homes in the United States that are treated with spray foam insulation qualify for both state and federal tax deducations.
Foam insulation blocks three types of heat transfer. The first, conductive heat transfer, is the flow of thermal energy through a substance from a higher to lower temperature region. The foam helps to block conductive heat transfer due to having a loose molecular bond. Also, the cells of the sprayed foam are filled with air which helps create a stronger barrier too.
Radiant heat transfer occurs when the heat energy is emitted strongly from warm surfaces and reabsorbed by other materials. The thermoset foams helps to reflect this radiant heat. This is because of the reflective surface as well as the cell structure of the foam.
The last thermal resistance type is convective heat transfer. This is when heat is created somewhere and is transported by water or air. Spray foam insulations has the ability to air seal which creates a airtight envelope within a building’s structure. This helps to block convective from the inside to the outdoor during heating months and vice versa during cooling months. This doesn’t allow the heat to escape through any gaps within the building’s envelope.
Some disadvantages to the use of spray foam insulation is that is can irritate the eyes and respiratory ract. Any direct skin contact can also cause inflammation. Overexposure to this can be dangerous. Because of these problems, many foams have been eliminated.
Spray foam insulation is typically non-toxic when it is cured. However while curing the spray foam does emit a gas that is dangerous. This makes full face and respiratory protection important to use during the process. After the foam is sprayed it expanded 30-100 times its original volume.