Installing porch roof flashing

Install Porch Roof Flashing

Water leakage is among the main problems for many people who have porches attached to their homes as the leakage usually happens at the junction of the porch and the exterior wall of the home. It can be quite a nuisance if you constantly have to deal with leaking around the house. Think how all those times you need to clean up the mess. Which is why it is better to fix the leaks before any further damage occurs.

The absence of the roof and improper flashing installation are the general causes for these leakages to occur. Although the installation of the roof flashing is not easy, you still can do it if you follow the steps carefully. Installing your porch roof flashing can be difficult but with the right steps, it is easy to do and not forgetting a little patience as well.

Here\’s how to it.

You will need:

  1. Ladder
  2. Metal break tool
  3. Hammer
  4. Metal roof lashing
  5. Galvanized roofing nails
  6. Gloves


  1. First, make sure to prepare the area where you want to install the roof flashing. Remove any faulty flashing if available. The lowest strip should be removed to install the flashing underneath if siding on the house wall abuts the porch roof joint.
  2. Then, determine how much flashing you need by measuring the length of the porch roof joint. Generally, most flashing comes in 10-foot long pieces. You will need to have two or more pieces soldered together to make one long piece if you prefer a longer roof joint.
  3. The most suitable material for the roof flashing is the aluminum as it is easy to work. If you prefer the premium quality, then choose roof flashing made from copper. Use tin snips to cut the flashing to size if the porch roof joint is shorter than the length of the flashing. Bend the flashing lengthwise in the middle according to the angle of the roof joint with a metal break tool. The flashing should be 8 inches wide where the 4 inches should go up the house wall and the other 4 inches should go on top of the porch roof shingles.
  4. Next, make a 10 degree bend on the shingle edge of the flashing approximately ½ inch from the edge. The waviness in the metal can develop after cutting. The bend will help to keep the flashing straight during installation.
  5. Then, place the flashing in the joint between the house and the porch roof. Make sure the wall portions of the flashing are flushed against the exterior wall and the shingle portion of the flashing should be on top of the porch roof shingles.
  6. Secure the flashing into place with galvanized roofing nails, keeping the nails as close to the edges of the flashing as possible. Avoid nailing in the inside of the flashing.
  7. Finally, replace the siding on the wall over the flashing.

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