Home Home Repair Repairing a Built-Up Asphalt Flat Roof

Repairing a Built-Up Asphalt Flat Roof


Many homes and commercial buildings have flat or low-sloped roof structures, and many of these feature asphalt-based roof systems installed on them. These built-up roof systems can be either smooth surfaced or have a gravel surface on them to help protect them from weathering. As these roof systems age and begin to break down, cracks and splits may appear around the perimeter, in the flashings and the general field of the roof.

In order to maintain these roof systems and maximize the life of the roof, repair these roofs as leaks occur.

General repairs to an asphalt built-up roof system can be accomplished quickly and effectively, using the using the following list of materials and hand tools.

Confirming Your Roof Type

An important step in completing an effective repair to your low-sloped built-up roof system is to confirm that your roof system is, in fact, an asphalt-based roof system. The following method of repair is only applicable to roof systems that are asphalt-based. If your roof assembly is a single-ply membrane, such as EPDM or TPO, the application of asphalt repair material to the surface of the membrane can damage the membrane and lead to a much larger patch or even full replacement.

Tools and Materials You Will Need

  • Trowel
  • Flat pry bar
  • Caulk gun (if using asphalt repair material in a caulk tube)
  • Utility knife with straight blade
  • Dust brush
  • Scissors
  • Asphalt primer
  • Roof cement
  • Reinforcing fabric–4″ or 6″