Flat Roofing Leak Repair

A home with a flat roof.
  • 2-3 hours
  • Intermediate
  • 100-500
What You'll Need
Roofing tar
Tar paper
1.5-inch roofing nails
Rubber gloves
Wooden plank

Flat roofing can often be more liable to suffering leaks due to the manner in which water, snow, and ice can gather on the roof. Ensuring that leaks do not cause more damage than necessary, it is prudent to have sufficient knowledge to repair any leaks that may occur. With a few steps, you will find it possible to rectify any holes that develop in the roof.

Step 1 - Examine

Inspect the surface of the flat roofing before commencing any work to determine the exact location of the repair site. In addition, getting an idea of the full extent of the repair necessary will make you aware of the number of materials required for the project. This step will also enable you to clear the area of any errant items that have ended up on the roof, such as leaves and toys. Use a broom to sweep the items from the surface of the roof.

Step 2 - Rectify Edging

Rectify the roll-roofing that runs around the edge of the flat roofing in the event that any of the seams have lifted. Look for any unevenness or changes to the appearance of the aluminum to determine where you must concentrate your efforts. Nail down any points where the roll-roofing has lifted from the surface, making sure that the drip edge leading to the guttering is intact.

Step 3 - Fill Depression

Depressions in flat roofing will usually be the cause of leaks. It is necessary to fill these in to create a seal. Put on a pair of rubber gloves and use a trowel to spread a thin coat of tar over the sunken area. Follow this by setting down a layer of shingles over the tar. Continue in this manner until the dip is filled.

Step 4 - Apply Patch

Patch the entire flat roofing surface by spreading tar over it once the depressions have been filled. Position a wooden plank on the roof, which you can rest on to move about the roof. Apply the patch material as far as is necessary to cover the areas necessary to patch. Spread the tarred area wider than the tar paper that will be applied to it. Lay the tar paper while the tar is still wet, taking care to push out any air bubbles with the trowel. Repeat this process with a second sheet of tar paper, flattening it down with the trowel. Use a sweeping motion with the trowel to flatten the paper into the tar. These layers will also allow you to cover any nails that have been used on the roof.

Step 5 - Finish

Check that all items used in the process of the repair have been removed from the roof before taking the last step to complete the project. Finish up by spreading sand over the surface of the roof, which will help it to last longer. The tar will make the surface waterproof and will allow the sand to stick.