Frequently Asked Questions (FAQ)
Dura-Foam Roof System
Q: To install a foam roof, does the existing roof membrane need to be removed?
Q: How thick is a Dura-Foam roof?
Q: Does the foam soak up water and leak if the coating layer is damaged?
Q: What colors are available for Dura-Foam roofs?
Q: Does Dura-Foam embed granules in the coating surface?
Q: How much does a Dura-Foam roof cost?
Q: Are Dura-Foam roofs environmentally friendly?
Q: Why are Dura-Foam roofs energy efficient?
Q: What R Value does a Dura-Foam roof have?
Q: How much cooler will my home be in the summer with a Dura-Foam roof?
Q: How much will I save on energy bills with a Dura-Foam Roof?
Q: What fire rating does a Dura-Foam roof have?
A: Often, an existing tar and gravel, torch down, single ply, modified bitumen, or cap sheet roof surface can be prepared to receive a foam roof without being completely removed. Any loose dirt or gravel is removed and the existing roof membrane is secured to the decking below. Decking below the membrane is inspected for dry rot by searching for soft spots and also slicing the membrane open in various locations. After preparation is complete, the clean and secured roof membrane makes an excellent surface for applying a foam roof. City requirements vary with respect to the number of roof layers that are allowed to be placed on top of one another. Most Bay Area cities allow a foam roof to be applied over one or two layers of built-up (tar & gravel) roofing. Some cities, such as Burlingame, always require a complete tear-off before installing a new roof system. In some cases where significant water or termite damage has occurred, Dura-Foam will recommend tearing off the existing roof membrane to replace damaged roof deck in a more cost effective manner.
A: Dura-Foam roofs are a minimum of 1″ thick on most commercial and residential roofs. Standard thickness over occupied areas on residential roofs usually is a minimum of 1.5″. Thickness may be greater to meet insulation or drainage requirements. For example, new construction requiring minimum R19 insulation receives 3.5″ of polyurethane foam over the occupied areas. Roofs with low areas will receive additional material to displace areas of problematic standing water. For example, an area on a roof where ponds are 2″ deep could have about 2.5″ of additional material applied to displace major amounts of ponding water. The coating layers that protect the underlying polyurethane foam are not included in the total roof thickness because these layers are relatively thin.
A: Spray Polyurethane Foam (SPF) installed by Dura-Foam is closed cell polyurethane and will not soak up water. The coating layers over the foam are depended on only for UV protection. Also, surface damage to the coating layer will not cause leakage, nor will surface damage cause the foam to soak up water. For a leak to occur, the thick SPF layer must be totally penetrated.
A: Generally, white coating is recommended because it is the most energy efficient and lasts the longest. Tinted coatings are available for special situations. Some cities require tinted coatings and sometimes reduced reflectivity is desired for visible roof surfaces especially in hill areas. Other coating colors are available for these types of situations such as Tan and Light Gray. Dark coatings are not recommended because they are not certified for Cool Roof Systems; dark coatings absorb too much heat and wear out too fast.
A: Dura-Foam, inc. does not recommend embedding granules in the coating for several important reasons. First, granules become dislodged over time and leave behind weak points in the coating surface. Granules are initially tossed onto wet coating by hand or with a hopper. When the granules hit the wet coating surface, they partially sink into the coating becoming embedded. As the roof ages, granules come loose and leave behind small holes or divots. These weak spots in the coating surface do not meet our standards for minimum coating thickness.
Second, our high quality roof coatings are not required to carry granules. Some inexpensive coatings require granules to pass fire and durability ratings. Our high quality coatings pass all fire and durability ratings without a need for granules.
Third, granules complicate the re-coat process creating unnecessary additional expense to property owners. Excessive coating is required to cover the rough surface texture of a granule roof leaving the property owner with excessive material expense. Also, the rough surface texture is difficult to clean properly further increasing re-coat expense unnecessarily. Roof surfaces with dirt or moisture in crevices between granules result in adhesion problems.
Admittedly, there are a couple of conceivable reasons out there for using granules, but we have concluded that any advantage for using granules is far outweighed by long-term disadvantages. Dura-Foam continues to apply even layers of high quality roof coating with no granules. Our high quality roof coatings meet commercial standards of durability and surface toughness. We have found that our methods offer more value to property owners, and that our roofs are less costly to maintain in the long-term.
A: Our roof prices are competitive with bids from other high quality roofing contractors. Dura-Foam estimators are prepared to visit the property and provide a formal proposal at no charge. Also, our estimators can give you a rough idea of price over the phone if your project is only in the planning stage and not ready for a formal proposal.
A: Dura-Foam roofs are friendly to the environment for several reasons. First, Dura-Foam roofs greatly reduce landfill waste because existing roof membranes are left on the roof surface and used as a substrate for applying the foam roof system. Also, landfill waste is reduced with foam roofs because Dura-Foam lasts the life of the building and never has to be replaced. Second, Dura-Foam is more energy efficient than any other flat roof system. Because Dura-Foam is classified as a Cool Roof System, it reduces “Urban Heat Islands” (increased outdoor temperatures in cities due to excessive concentration of dark roads and roof surfaces). Third, Dura-Foam is 100% non-toxic. Our polyurethane foam is totally inert. During the installation process, tenants are safe to dwell inside of the property.
A: Dura-Foam is more energy efficient than any other flat or low slope roof system. The reflective surface coating is classified as a Cool Roof System and is certified by Energy Star for its efficiency. Dura-Foam is also extremely energy efficient because of the insulation properties of polyurethane foam. The polyurethane foam applied on our roof systems has no joints for heat to escape (unlike foam board insulation installed in 4’x8′ sheets on other roof systems). In addition, the placement of the foam roof system on the outer most surface of the roof structure improves energy efficiency by keeping the underlying mass of roof structure at a stable and comfortable indoor air temperature. With other roof systems, the roof surface heats up and cools down with outside air temperature working negatively against the desired indoor temperature. For example, a tar and gravel or cap sheet roof typically reaches temperatures around 160º F on a warm summer afternoon. This hot mass of material transmits a lot of heat through underlying insulation (if any) and then throughout the entire roof structure resulting in uncomfortably hot indoor air temperatures or excessive cooling cost. Dura-Foam roofs avoid this dilemma by providing highly efficient insulation at the outermost layer of the roof structure.
A: R value is a measurement signifying a material’s resistance to heat transfer. A material with a high R Value has a high resistance to heat transfer. R value of a Dura-Foam roof is measured by using the conservative factor of R 6.25 per inch of polyurethane foam. At this rate, a foam roof having a thickness of 1.5″ adds an R 9.4 to the roof structure. The actual R value of our polyurethane foam is higher than 6.25, but we use this number to comply with standard building practices accepted by the International Code Council (ICC).
Knowing of how R values are calculated helps to understand why polyurethane foam insulates more effectively than fiberglass and other types of insulation. The test for R Value takes place in an environment with zero humidity and zero air infiltration. In the real world, fiberglass and other types of insulation absorb moisture due to varying humidity levels and they also allow air infiltration. On the other hand, our Spray Polyurethane Foam always has zero humidity and zero air infiltration because it is is closed cell and seamless. Inch for inch, polyurethane foam is has a higher R value and works more effectively than any other type of building insulation. For this reason, a Dura-Foam roof with as little as 1″ of foam will completely transform the comfort and efficiency level of a building.
A: With a Dura-Foam roof, expect to stay 10ºF to 20ºF cooler on hot summer days if you are in a home or building with no air conditioning.
A: For buildings with air conditioning, cooling costs are typically reduced by 30% to 60%. Heating costs are typically reduced by 30% to 50%. Common factors that affect actual energy savings include insulation quality of the building’s walls and windows, and the amount of insulation in the existing roof structure. The most dramatic energy savings occur in homes and buildings that have little insulation in the existing roof structure.
A: When installed over non-combustible decking or an existing Class A roof structure, a Dura-Foam roof has a Class A fire rating (the highest rating available).