Spray polyurethane foam (SPF) has become a popular choice of materials especially on flat roofs. Sprayable foam is created by the combination of two component mixtures that come together at the tip of a gun. The resulting product is expanding foam that can be applied on practically any surface. It is used on low-slope and flat roofs for both residential and commercial buildings. SPF is considered energy efficient, less expensive than other materials, and is available in a variety of colors.
How Foam Roofing Works
Foam roofing is available as a spray and so provides a seamless product that can protect buildings from the elements. The application technique permits the foam to directly adhere to the roof with no flashing or seams, thus avoiding many of the problems associated with other roofing products that permit leaks to develop.
Spray foam roofing is manufactured from a variety of chemical elements which affect the safety of installation, material performance, and environmental green qualities. Base products include polyisocyanurate, tripolymer, polystyrene, and closed- or open-cell polyurethane such as icynene.
Professional installation of SPF is important to prevent any number of installation mishaps. Homeowners generally do not have the skills and equipment to install a foam roof themselves.
Warranties on Foam Roofing
Warranties usually cover manufacturing defects. They will also guarantee that the foam meets published physical properties when applied, cured, and tested according to the company's standard procedures. Liability is often limited to replacing the materials within ten years of installation. Warranties do not cover damages caused by natural disasters, intentional or negligent acts, deterioration of building components (such as the substrate), or harmful chemicals which may come into contact with the SPF.
Common Problems with Foam Roofing
As with any roofing surface, punctures in the material can occur and cause water to seep in under the foam, through to the insulation, and possibly to substrate layers. If the application of the SPF occurs when the roof isn't completely dry, blisters may develop leading the foam to separate from the roof. Sometimes excessive foot traffic on an SPF roof can cause scrapes or tears in the foam. Always visually inspect the roof after anyone has been walking around up there.
Some foam roofing products are manufactured without the use of solvents and formaldehydes, and therefore, do not have the negative indoor air quality sometimes associated with those chemicals. SPFs that use water as a blowing agent are more environmentally friendly than those that do not; foams that do not contain chlorofluorocarbons (CFC's) are also better for the environment. Spray foam cannot be re-used and ends up in landfills when it needs to be removed.
Popular Foam Roofing Brands
- Dow Chemical
- Dura Foam