faq's about spray foam roofing
What is sprayed polyurethane foam?
Sprayed Polyurethane Foam “SPF” is a 2-part liquid that when spray applied, expands to 30 times its volume to form a monolithic, seamless, lightweight roof surface normally used in low-slope roofing systems.
Can sprayed polyurethane foam be applied over any surface?
SPF requires a clean surface for proper application. It must be dry, free of contaminants like oil, and properly fastened to the substrate in accordance with proper building codes.
How long can a sprayed polyurethane foam roof last?
SPF has been used as a roofing and insulation material for more than 45 years. Foam roofing systems have proven themselves through comprehensive, independent studies to be dependable, long lasting, and very affordable. RPC Industries, Inc. has been successfully installing foam roof systems for more than 30 years and we are still maintaining some of our original roofs.
What kind of R-value does a sprayed polyurethane foam roof have?
SPF has an R-value of 6.1 per 1 inch thickness, enabling it to provide more thermal resistance with less material than any other type of roofing insulation. It also produces an energy savings of up to 30% when compared to alternative roofing systems.
Can I walk on my SPF roof?
Yes, SPF roofs can be walked on.
How does SPF reduce energy use?
SPF reduces energy use in the following ways:
· Has high R-value per inch (open-cell 3.5 per inch and closed-cell 6.1 per inch)
· Eliminates air infiltration by providing a continuous air barrier
· Prevents moisture infiltration
· Reduces convective currents in walls and attics
· Eliminates wind washing
· Provides the correct environment so that the ventilation system performs more efficiently
· Minimizes dew point problems and condensation
· Avoids thermal bridging
· Resists heat movement in all directions
How is a SPF roof system maintained?
SPF roof systems should be inspected semi-annually and after events that could cause physical damage. Small (less than 3″ diameter) dents, cracks, punctures from dropped tools and wind driven debris can be repaired with an elastomeric sealant compatible with the SPF and coating system. More extensive damage can be repaired by reapplying SPF. Typically SPF roof systems are re-coated every 10 – 15 years, depending on factors specific to the roof and original warranty terms. Re-coating extends the service life of the SPF roof system.
Where can I use an SPF roofing system?
SPF has excellent adhesion to a variety of substrates including, BUR, clay and concrete tile, shingles, metal, wood and concrete. Since they add little weight and can be applied in varying thickness to add slope and fill in low areas, SPF roofing systems are often used to recover over existing roof systems. SPF roofing systems excel where:
· Additional insulation is desired
· The roof substrate has many penetrations
· The roof deck is an unusual shape or configuration
· The roof is in a severe weather environment (hurricanes, hail, etc.)
· Lightweight materials are required
· Slope must be added to provide positive drainage
· It is desirable to keep existing roof covering
How do SPF roof systems compare in cost to other roof systems?
SPF roofing systems are cost competitive with other systems. Life Cycle Cost Analysis performed by Michelsen Technologies demonstrated that over a 30 year life span, SPF roof systems cost between 10% and 50% less on average than comparably insulated membrane roof systems. (Averages were based on SPF roof system recoats of every 6, 10 and 15 years. A copy of the Life Cycle report is available from SPFA.)
Why do you need coatings or coverings over SPF?
SPF is water resistant without other coverings; however, the surface of SPF can deteriorate under the sun’s ultraviolet (UV) rays. Typically, elastomeric coatings are used to protect the SPF against UV radiation.
Is foam roofing a green product?
Yes. Properly installed SPF roof systems can easily last 20 years or longer. In fact, properly maintained SPF Foam Roof systems can last the life of a property. A related study was performed in 2004 by Michelsen Technologies and involved a SPF roofing system life-cycle analysis in five climate areas of the United States. Analysis of evidence led to the conclusion that the average SPF roofing system costs 15% to 50% less to install and maintain than a conventional membrane roof system over a thirty-year time period. The study reported costs based on 6-year, 10-year, and 15-year re-coat schedules.
At the 1996 Sustainable Low-Slope Roofing Seminar, Oak Ridge National Laboratories described green construction roofing systems as “roofing systems that have a long life, low maintenance, save energy, add durability to buildings, control moisture in buildings, and contribute very little to the waste stream.” Foam roof systems meet every requirement of the definition of green roofing provided by Oak Ridge National Laboratories. Foam roofs provide excellent insulation, which cuts energy usage, which lowers fossil fuel consumption, ozone depletion, and prevents global warming. Often light-weight, foam can be applied over an existing roof-membrane (i.e. the original membrane can be re-used), which prevents landfill waste. Landfill waste is a significant issue with roofing. According to a 1999 survey by the National Roofing Contractors Association (NRCA), more than 68.5 percent of the $11.3-billion low-slope re-roofing market includes tear-off and replacement of the existing roof membrane. Foam roofing is also renewable; after installation, proper maintenance only requires periodic re-coats, which can allow the Foam Roof System to last the life of the building.
Will adding foam to my roof reduce my energy costs?
Absolutely! SPF is one of the most efficiently energy and cost effective materials used to insulate a building; both on top of a roof or inside walls or attics. If you are looking to have a smaller electric bill and keep your office complex cool during the summer (or keep them warm in the colder months) SPF is the way to go. Contact us at 1-(877) 772-7663 or email us through the Contact Us page.
Where can I find out more about SPF?
Read our sections on foam roofing, foam roof re-coating, and foam insulation or go to www.sprayfoam.org.