How to Install a Roof Flashing to Flat Roof Rubber

What You'll Need
Rubber roof flashing
Paint brush
Rubber cleaning solvent
Cleaning cloth
Bucket of warm water
Hand roller
Rubber seam tape

When it comes to flat roofs, most people prefer to use rubber since traditional roofs rely on gravity to keep the water away from the structure of the home and since a flat roof is just that, flat, gravity is unable to pull the water away. The biggest obstacle for a rubber roof is where things such as chimneys and pipes protrude. The rubber has to be cut away in order to accommodate these. This creates seams. Seams are the number one area where leaks occur on a rubber roof. The easiest solution is to ensure your roof is properly sealed at all seams and to use roof flashing around all joints.

There are different options for rubber roof flashing. There are rubber roof flashing sleeves as well as single pieces that need to be wrapped around the protruding object. Although the sleeves are easy to install as they are precut, they do not always fit properly. An improper fit will cause leaks.

Step 1-Prepare the Joint for Flashing

It is extremely important to work with clean, dry rubber. This said, your first step is to brush away any debris that might be on or around the area. Thoroughly wash both the post and the rubber with warm water and allow to dry. Remove the backing of the rubber roof flashing and set the sticky side up. The flashing already has an adhesive built right on it. 

Once the post and the rubber are completely dry, using a paint brush, apply rubber cleaning solvent to both the sticky side of the flashing and to the post itself. Apply the solvent around the post where the flashing will be placed. Allow this to dry for 5 to 10 minutes.

Step 2-Apply the Flashing

Fold the piece of flashing in half the long way ensuring the adhesive side is on the outside of the fold. With the opening pointing upward, secure the flashing to the post by tightly wrapping it around. Ensure the bottom of the flashing is flush with the roof. After you have wrapped it around 3 of the 4 sides of the post, begin unfolding the flashing. Push the piece of flashing that was folded upward down so that it covers the roof. Do so carefully to ensure there are no bubbles. Now that you have it unfolded around the first three sides, finish wrapping the flashing around the post. Unfold the last side.

If any air bubbles did form, you can remove them with a small hand roller.

Step 3-Secure the Flashing and Admire Your Work

To reinforce the flashing, apply seam tape around the top where the flashing first comes into contact with the post. Also apply the seam tape to the area where the two ends of the piece of flashing come into contact. There is no drying time for self-adhesive flashing. Once you have placed it, it is secure. This gives you the opportunity to immediately inspect your handy work and take pride in a job well done.