Installing Porch Roof Flashing To Prevent Leaking

What You'll Need
Roof Flashing
Galvanized Roof Nails
Gloves (optional, but will save a lot of wear on your hands)
Metal Break Tool

If you have problems with your porch roof leaking, it is often due to a lack of flashing, or poorly installed flashing. Flashing is a thin strip of weatherproof material installed to deflect water from seals and joints to protect your porch and home from damage.

Flashing can be difficult to install, so make sure you are following the directions carefully and taking your time.

Grab a Friend

This is a job that is much easier with two people. You will be climbing up and down a ladder, and working with long sections of metal. If you have another person working with you it can make it much easier and safer.

Prepare the Area

If your current flashing is not doing the job, you will have to remove it before installing new flashing. If you have siding, wou will also have to remove one panel of siding closest to the porch roof joint so you can reach the flashing.

Take Measurements

You need to get accurate measurements. Measure the porch joint length to find out how much flashing you will need. Flashing generally comes in 10- foot sections. If the roof joint is longer, you will need to solder two pieces together to make it fit.

Choose the Material

Aluminum is the most popular choice for roof flashing since it’s so easy to work with. If you are looking for a higher quality material, you may want to consider tin, sheet lead or copper. Aluminum can work well,though, if you take your time installing it.

Prepare to Install

Cut the flashing with tin snips if you need to cut it. Use a metal break tool to bend the flashing according to the angle of the roof joint. Flashing is generally 8 inches wide with 4 inches going on the wall of the house, and 4 inches going on the top of the roof shingles.

You need to make a bend of 10 degrees one half inch from the edge. The metal may wave after you’ve cut it, and this bend will help to keep the flashing straight while you install it.

Install the Flashing

Place the flashing between the joint of the house and the roof. The flashing on the wall should be flush against it, and the porch roof portion should be on top of the shingles.

Nail the flashing securely in place using roofing nails. Try to keep the nails as flush as possible to the edges. If you nail on the inside it will damage the flashing and make it less effective.

Replace the Siding

Once you have the flashing installed in all the areas you need it, replace the siding panels that you had to remove. When installed correctly the flashing underneath it should not be visible.