Flat Roof Definition

Types

• According to "This Old House" magazine writer Max Alexander, business and homeowners can choose between different types of flat roofs based on resiliency, look and installation. Property owners can purchase a built-up roof (BUR), which is comprised of multiple plies of roof materials laminated together with tar and held together by gravel. Flat roofs built with modified bitumen (also known as roll asphalt) are made of single- or multiple-ply rolled materials, and can be used in conjunction with BUR systems. Homeowners can also choose to install a rubber membrane, which is typically installed with stone or glue. The fourth type of flat roof is made with sprayed polyurethane foam or SPF. The foam creates a layer with seals and protects the surface from weather damage.

Disadvantages

• Some of the disadvantages of flat roofs include increased exposure to severe weather. For instance, sloped roofs allow rain and snow to run off more easily than on a flat roof. Water, snow and ice can quickly accumulate on flat roofs, causing damage and deterioration. As a result, flat roofs must often be repaired or replaced if owners neglect to keep them clean and covered with materials such as rubber membrane systems.

Improvements

• While traditional flat roofs are subject to wear and tear, small improvements and reinforcements can extend the longevity of your roof. For instance, coating your flat roof's surface with fiberglass can protect from leakage and ripping. Also, laying flat roofs as continuous sheets rather than fixing individual panels with joints and welds can prevent water from pooling and seeping through the material. Additional features that can help improve your flat roof include extra insulation to keep in heat and increase your home's energy efficiency.

Misconceptions

• Although flat roofs are technically horizontal, they are usually not built completely flat. According to "This Old House" magazine's Tom Silva, more modern buildings have flat roofs that are built on a slight incline. A flat roof's slope is usually at least one-eighth inch per foot of roof. Some roofs also are built on an incline heading in different directions. This effect encourages water to drain towards scupper holes leading to downspouts, or vertical pipes alongside the building.