A flat roof can be made of almost any kind of roofing material, but three options stand out: built-up roof, modified bitumen, and rubber membrane. What exactly are these materials and what makes them more popular than others?
Built-up Roof (BUR)
A built-up roof is a type of flat roof that consists of multiple layers of waterproofed material such as tar paper or fiberglass mats. Thin layers of stone, gravel, or small grains are placed between each material layer to keep it in place and to provide better weather resistance.
A built-up roof’s greatest advantage is its cost-efficiency. Aside from being one of the most affordable roofing options, a built-up roof offers great fire resistance. This type of flat roofing also offers great thermal resistance, making it a cool option for homes in warmer areas.
Modified bitumen
A modified bitumen flat roof is made of a single-ply roof layer with a mineral-based surface. The bottom part of the material has an adhesive surface, which can be activated by heating with a blowtorch. Newer versions have a protective layer covering the adhesive side that can be peeled off before installation.
Modified bitumen roofing strikes a fine balance between durability and cost, being just a bit more expensive than a BUR. The mineral-based surface has some reflective properties, reflecting a lot of heat away from the home, which helps keep it cool.
Rubber Membrane
A rubber membrane roof features a continuous stretch of durable rubber material which is secured in place by staples, adhesives, or ballasted in place. The rubber used for this kind of roofing is similar to the stuff found in tire tubes, and is very durable.
Aside from being damage-resistant, a rubber membrane roof can easily be repaired by patching over punctures or scratches. This type of roofing material may seem to be more expensive than the previous two options, but rubber membrane roofs are also more durable than either.
Do you know what it takes to keep a flat roof in good condition? Check out these maintenance tips as we reach the last part of this blog series.
