How to Repair Roof Flashing

What You'll Need
Roofing cement
Caulking gun

Roof flashing is essential to the construction and maintenance of your home because it helps prevent leaks that can damage your home. It is also designed to withstand many weather conditions, from extremely high temperatures to extremely low temperatures. If you see large water spots on the ceiling inside your home, then your roof flashing is most likely damaged. You can easily repair the roof flashing and prevent further water damage by sealing it up. Repairs should be taken care of immediately before any permanent and costly damage is done to the home.

Step 1 – Climb the Ladder

Safely position a ladder that is high enough to reach the roof before climbing up. Have a friend or family member stabilize the ladder if needed. Make sure to do this on a clear day and when the sun is still out so you can see well.

Step 2 – Locate Roof Flashing

You can find roof flashing around dormer windows, the chimney base, skylights and pipes that protrude from the roof. Carefully and thoroughly check all of these roof flashing areas to find out which one is causing water damage.

Step 3 – Drip Edge

If the seal between the shingles on the drip-edge is broken, apply roofing cement sealing. This will be placed 6 inches below the shingles and along the drip edge. Make sure that you do not apply the roofing cement along the eaves.

Step 4 – Valleys

Lift the shingles that are near the valley flashing. Apply roofing cement 6 inches from the edge, below the shingles.

Step 5 – Seal Vent Flashing

Use a caulking gun to seal the vent flashing. Apply enough bead as determined by you between the vent pipe and the flashing. Then spread the roofing cement under the shingles that are surrounding it. There may also be a flashing flange next to the vent flashing, in which case you will need to fill the seams.

Step 6 – Chimney

If you live in an old house, you probably have a chimney, where you will find mortar and caulking that connects the flashing to the chimney. Remove with a hammer and chisel and sweep away any debris before moving on. After cleaning up the area, use the caulking gun between the cap flashing and chimney, and then apply roofing cement around the cap flashing and step flashing.

Step 7 – Dormer Windows

Use the chisel to remove caulking along flashing and clean the debris. Lift the shingles and apply roofing cement underneath, and re-caulk the seams in the flashing.

Step 8 – Skylight

If your house has a skylight, look for the flange, which is a metal girdle that is found on the skylight box. Lift the shingles and then apply roofing cement under the shingles and over the joints going up to the flange.