There are different flat roofing options available to address different needs. Understanding what each one is capable of will help you gauge which flat roof will work best for you.
BURs have been around for over 100 years in the United States, made up of alternating layers of reinforcing fabrics and bitumen topped with surfacing like mineral- or fiberglass-surfaced cap sheets, elastomeric or aluminum coatings, hot asphalt or aggregate like gravel. The flat roofing option can also be fire-resistant, but this depends on the surfacing used. Gravel, for instance, has high resistance to fire. Because it is made up of several plies of material, BURs are highly durable. However, having several plies of material also makes it more difficult to handle, making installation a bit troublesome, although the more plies there are, the longer the service life of the roof is.
A single-ply flat roofing option, EPDM stands for Ethylene Propylene Diene Terpolymer. It is the most common of thermoset membrane roofs (there are five), consisting of two compounds derived from natural gas and oil, propylene and ethylene. Sheets can go as wide as anywhere between 7.5 and 50 feet and as thick as 45 to 60 mils. Mostly available in black, EPDM is sealed at the seams with liquid adhesive or a special tape. Unlike BURs, it doesn’t require surfacing but is easy to repair.
A thermoplastic single-ply roofing membrane, TPO (thermoplastic olefin) can be repeatedly hardened or softened, sealed at the seams through heat welding. It usually comes in white (making it an excellent cool roof option by default) and features flame-retarding and UV-absorbing properties. Each TPO sheet is typically 6 to 12 feet wide and 40 to 100 mils thick.
A cross between BURs and single-ply roofing membranes, modified bitumen is a flat roofing option offering durability and installation ease. It expands and contracts well, allowing the roofing material to move in time with frequent and constant temperature changes to reduce wear and tear, and installs like a single-ply membrane despite featuring more than one layer of material. Typical surfacing options used in modified bitumen roofs include: smooth liquid-applied surfacing, metal foil laminate and mineral or aggregate surfacing.
Found the perfect flat roofing option? Make sure your property is ready for an installation by brushing up on a few things. Read on to learn more!