How to Repair Roof Flashing Around Roof Vents

What You'll Need
Finishing nails
Asphalt flashing cement
Steel wool

Knowing how to repair roof flashing is important to help prevent leaks from your roof. The flashing is designed to prevent water from seeping in around vents, in corners, and other areas where the roof needs to connect with other elements, such as around joints and edges. Roof flashing can be found in various materials such as aluminum, asphalt and tin. The most common flashing used is asphalt roof flashing because its easy to use and low in cost. Most brands of asphalt roof flashing is peel and stick and is available in tape form. Rolls of asphalt roof flashing can be purchased at most local hardware stores and online. Based on the size of the project you may want to consult a professional roofer, but repairing flashing is a job that can be done in a fairly short period of time, and is cheap to do.

Step 1: Preparing the Area to be Repaired

Remove all the shingles surrounding the roof vent. Once the shingles are removed, locate the section to be repaired and use steel wool to clean the area where the new flashing will be placed. Cleaning the area first is important to properly repair flashing around roof vents. A little prep work provides a smooth surface for the new flashing and helps prevent gaps and area pockets underneath the new flashing.

Step 2: Measuring and Cutting Flashing

Measure area where the flashing will be used. Asphalt roof flashing tape used to repair flashing around roof vents comes in various widths and thicknesses. Select the proper one based on the size of the job and the degree of protection that will be needed. Wearing protective eye-wear and gloves, cut flashing to size using heavy duty scissors or a utility knife. Cut enough flashing to cover the area where it will be applied allowing for slight overlap to protect from future leaks.

Step 3: Applying Flashing

Remove backing from asphalt flashing tape and stick in place with adhesive side down. Place flashing along roof vent overlapping to ensure there are no gaps. Smooth each piece by hand to form a firm bond. Apply asphalt flashing cement along edges of flashing and around the roof vent to create a waterproof seal.

Step 4: Finishing

Allow the asphalt flashing cement to dry completely. Once dried, using a hammer and finishing nails, install shingles according to manufacturers directions. After the roof shingles are installed it is important to test for leaks. Use a water hose to run a constant stream of water on the section that was repaired. While the water is running check the interior of the house for visible signs of wetness or leaking. It may take 10 or 15 minutes for you to test the area.