Foam Roofing: The Superior Flat Roof Solution

What is Sprayed Polyurethane Foam?

Polyurethane spray foam has been used as a roofing material for nearly 5 decades. Extensive testing through independent studies have shown that foam roofs are long lasting, affordable, and excellent for waterproofing and insulation as well.

Sprayed Polyurethane Foam is based on two components: isocyanate and polyol, which must be fed through a heated and pressurized hose, and applied to a roof surface with a spray gun. The components combine as they reach the roof surface, rising for about three seconds and curing in about 1 minute. As the liquid rises, a seamless, smooth and stable layer is formed. The surface must be properly prepared and clean (no oil or dirt should be on the roof surface) and outdoor conditions must not be at high humidity levels for the foam to self adhere effectively. No loose aggregate (gravel) should be on the surface, and the substrate should be securely attached to the roof surface. After the foam is applied, 1-2 layers of elastomeric cool roof coating (about 30mil) is applied to protect the roof from ultraviolet rays, and keep the roof surface temperature low, which enhances the efficiency of the underlying insulation.

Below: A polyurethane foam roof in progress. This bare foam will receive a base coat and top coat to extend the roof life and protect the foam from long term UV degradation. This roof will receive a cool roof coating which will reflect heat and maintain much cooler roof surface temperatures than a dark colored (non reflective) roof material.

Foam Roofing Advantages

Sprayed polyurethane foam (SPF) roofing has many advantages over traditional roofing materials such as BUR (built up roof), PVC (polyvinyl chloride based highly flexible plastic membranes), TPO (thermoplastic polyolefin), and EPDM (rubber roofing). For more information on the strengths or weaknesses of these roof types there are other posts on this forum such as:

Foam vs Tar & Gravel: forum2/topic13.html
Common Flat Roof Materials: forum2/topic9.html
Tar & Gravel vs Mod Bit: forum8/topic15.html

Below: A foam roof receives a reflective white base coat. The life of a foam roof can be extended to the life of the building by adding a layer of cool roof coatings to the foam roof every 5 to 15 years (depending on wear, location, and initial thickness). Foam roofs can last 20 or more years with virtually no maintenance, and extending roof life to 40 years or more requires very little.


The cost of installing a foam roof, is about the same as installing a traditional roofing system along with a similar level of insulation. Some benefits of foam roofing include:

*The best insulator: sprayed polyurethane foam consists of about 1 million cells per square inch, giving it R-values of 6 to 8 (depending on the formulation), and foam is airtight as well. Both of these factors make it superior to any traditional insulation types, and just one inch of foam will greatly improve the performance of any underlying insulation (by reducing surface temperatures and blocking air movement).
*Lightweight: SPF roofing material is incredibly light at 50lbs per square, compared to 800lbs or 100lbs respectively for BUR (built up roofs) and single ply roofing. This also means foam can be installed on top of an underlying roof substrate, which diverts landfill waste and preserves the environment. And, due to the light weight and seamless nature of sprayed foam, it can be used to safely build up low areas, to correct both roof sagging and ponding.
*Flexible: spf foam will conform to any surface it is sprayed on, making it ideal for roofs with large amounts of protrusions such as vents, pipes, chimneys, skylights, ac units, and other equipment.
*Seamless: polyurethane closed cell foam creates a single seamless and waterproof barrier. The lack of seams or joints prevents the roof from having the weaknesses of traditional roofs that eventually result in leaks.
*Long life: a foam roof lasts the life of the building. This also prevents landfill waste and conserves resources.
*Ease of Installation: foam can safely be installed while occupants are inside without interrupting any currently running operations.
*Energy Savings: spf foam roofing can save as much as 25% to 40% on both cooling and heating bills, effectively paying for itself in the long run (and possible in as little as 5 years depending on energy cost savings).

SPF Foam is Inherently Waterproof

Since polyurethane foam is made of millions of tiny closed cells, it remains waterproof, even if the coating is cracked or penetrated. As an example, the New Orleans superdome had thousands of hairline cracks due to hailstorm damage, yet no leaks occurred, despite the fact that no repairs were made for a decade. Only complete penetration of the foam (a hole all the way through) will result in a leak, and this can be repaired to full function with any elastomeric caulking material.
Cool Roof Coatings
Elastomeric coatings can extend the life of a foam roof indefinitely by preventing exposure from ultra violet light. Generally, a light colored and reflective (cool roof) coating should be used. This keeps the roof surface temperature within 10-25 degrees F of the ambient temperature of the surrounding area.

Summary

Sprayed Polyurethane Foam Roofing (SPF roofing) is the greenest (most environmentally friendly) and economical roof for your home. SPF roofs are both seamless, lightweight, making it a monolithic barrier against the elements, improving the quality of life within the structure, cutting energy costs, and diverting landfill waste. Energy star approved cool roof coatings further enhance the performance of SPF roofs, keeping the underlying building both cool in summer and warm in winter. Sprayed polyurethane foam truly is the superior flat roof solution.

For more information, here is an excellent, and comprehensive article on Foam Roofing:
Foam Roofing Article

Foam clearly has all the advantages. It's a technologically superior material engineered for roofing applications. With an R-Value of 7, its easy to reach or exceed most building insulation standards in most climes without stepping foot inside the building. And, considering that traditional R-values don't measure gas trapping or vapor trapping, foam is effective even beyond traditional ways of measuring insulation.

Find a local Foam Roofing contractor.