Flat Roof Covering Types

They are also commonly used on sheds and other out buildings. Flat roofs typically have a slight pitch to them to channel water off the roof or to drains in the center of the roof.

As long as a flat roof maintains its designed pitch a tar and gravel covered flat roof works fine. However, if the gravel is disturbed, or ice dams build up, which is often the case, water has the tendency to pool in areas of the roof. Inevitably the pooling water leads to roof leaks and structural stress on the roof framing.

As a result of these issues and concerns with tar and gravel flat roofs, membrane liners became the flat roof covering type of choice. Whenever possible, one large continuous sheet of rubberized membrane material is used to cover a flat roof. Often, however, multiple sheets are needed. In these situations they are bonded together with a special adhesive. Another alternative for covering a flat roof is to use sealed metal roofs made out of tin or copper. These types of flat roof coverings, however, are quite expensive and not often used in residential building. Asphalt roofing shingles are also occasionally used as a flat roof covering, however this flat roof covering method is typically limited to sheds and other out buildings.

Though flat roofs lend themselves for additional outdoor space, precautions have to be implemented to protect the roof covering from damage. If there is a desire to use the flat roof as outdoor space, often a deck is built over it to protect the flat roof covering from damage. In some cases topsoil, and lawn and small plants are installed over the membrane liner to produce a green area on the roof.