The initial research for polyurethane foam was conducted in 1937 by Otto Bayer and his team. In the mid-fifties, the commercial production of polyurethane foam began. By the early 1970’s, polyurethane foam was used for exterior roofing applications. Polyurethane roofing has been around for over a half century!
Research projects by the National Roofing Foundation (NRF) and Arizona State University have documented the performance of SPF roofing systems over the course of several years. throughout the United States showing that customer satisfaction level remained high for the roofing system. There is no known lifespan of a Spray Foam roof that has been properly applied and maintained. Many of the earliest applications of foam roofing are still standing. Your spray foam roof may well last the life of your building.
A foam roof is actually similar in cost to a typical Built Up Roof (BUR) or a single ply roof (EPDM). (On our Home Page, see the sections explaining these roofing systems). Spray foam roofs start at $4.00 – $5.00 a square foot installed, but depending on the initial work required on your existing roof, it could cost $6.00 – $7.00 per square foot.
When you consider a 15 – 20 year time frame, even with periodically maintaining your roof by recoating your roof, your spray foam roof is the most cost effective choice. Your energy savings from cool roof coatings alone over that time period will reduce the cost of your roof. Depending on your energy savings and if you qualify for local power company incentives, your return on investment on your 3 pound density foam may be under 5 years.
Imagine a block of plastic filled with millions of small closed air bubbles that water can not penetrate. That block will float because the water cannot penetrate it. The same is true for the Spray foam roof and that is why it is such an effective solution on flat roofs where ponding water has been a problem. The water will not penetrate the spray foam. And because spray foam is custom applied to each roof, then low lying areas can be filled in.
SPF and elastomeric roof coatings can be installed in all geographic areas of the United States. Most applications occur when the target temperatures are 45°F to a very warm 120°F. While moisture— such as rain, frost, dew, and snow— on the substrate will prohibit the application of foam or coatings; still, there are ways around this application barrier. The SPF industry has established guidelines stating that spray foam is not to be applied when the temperature is within five degrees of the current dew point. Applicators typically monitor the weather conditions through weather data and by using handheld electronic measurement tools.
The spray foam used in roofing is plastic with “closed cell” with millions of small trapped air bubbles. The inert polyurethane base materials are the same materials used in foam mattresses and are as safe as the foam pillows people use on couches or in the seat cushion inside your car.
It is common to see birds on top of any roof system. When a rubberized coating is properly covers the foam, the birds will not bother the roof. Any slight surface imperfection, caused by birds or humans usually will not cause a leak and can easily be repaired with a sealant (compatible with the roof coating) will repair the spot.
A spray foam roof is capable of sustaining the weight of a normal person. The Spray Polyurethane Foam Alliance (SPFA, www.sprayfoam.org) and National Roofing Contractors Association (NRCA, ) both suggest a minimum compressive strength of 40 pounds per square inch or higher when used as a roofing foam. At AFU, we typically use pounds per square inch. If a maintenance person damages the roof, it can be repaired with the proper caulking and coating to protect it.
The SPF industry has spent several hundreds of thousands of dollars testing their roofing systems at independent laboratories. One such lab is the Factory Mutual Research Center (FMRC), which is owned by an insurance group. They do insure — as well as test — SPF roofing systems.
10. SPF roofs are soft and don’t stand up to high winds, fire, and hail damage. False The FMRC has tested several industry members’ SPF roofing systems for wind, fire, and hail resistance. The SPF roofing systems continue to provide some of the best results in this battery of tests for roofing systems as they relate to performance during extremes.
SPF has been in use for more than 35 years. As such, it was one of the early insulated roofing systems that promoted the use of insulation and light-reflective roof coatings to help save energy. The use of seamless insulation and white or light-reflective coatings have been in use for longer than most of the cool roof-type roofing systems that we find in today’s market place. Many of the industry’s SPF roof system components have been charter partners in the Energy Star Roofing Program to save energy. Several industry companies are active in the Leadership in Energy and Environmental Design (LEED) program, among others.
Building owners are usually told to remove their SPF roof for one of two reasons. The first reasons is that the roofing contractor does not have the knowledge, equipment, or capability to install or repair the SPF roofing system. The fact is that the repair of a SPF roof is normally a lower-cost solution than the removal of the SPF roof. Unfortunately, a roof contractor who does not have this capability will recommend tearing the SPF off and installing a roof he can do — regardless of whether it is in the best interest of the customer or not.
The second reason is that the roof in question is a poorly installed, designed, or maintained SPF roofing system, and it may be best to tear it off and start over. Even though most of the applications that I have seen over the past 35 years have been good-performing SPF roof applications, this highlights the importance of the next point below: Make sure you use a roofing company that can properly install a spray foam roof!
It is true that you should make sStart by contacting either of the two trade associations and researching the requirements for the SPF roofing system to be correctly installed. Check out the SPF contractor, just as you should do with any roofing contractor or construction professional. Ask to see past work that can be visited, or ask for references that you can call. Design professionals can build up the best specifications with the best products, and yet the project may not be done by the best applicators. We have many applicators in our industry who have proven themselves and their workmanship for more than three decades or longer. They have a history of putting down good SPF roofing systems. Those that do not have knowledge of a product or system create myths. Those that compete against a particular system can create them. Those intending to either install or purchase the material or end product should understand the facts of any particular construction material, design, and proper application. Spend a little time and look into the system, and you will be very pleased with its performance when properly installed.
(The above information includes excerpts from SprayFoam Magazine, written by Jim Andersen, BASF Polyurethane Foam Enterprises. For more information click here )
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