How to Repair a Leak where a Patio Roof Meets the Main Roof

Lead Image
  • 2-4 hours
  • Beginner
  • 20-100
What You'll Need
Pressure washer
Work gloves
Roofing cement
Caulking gun
Putty knife

When learning how to repair a leak where a patio roof meets the main roof, there are some important considerations you should make such as whether the patio roof will be able to support your weight. Patio roofs are typically weaker and less reinforced than main roofs, but holes can easily be repaired with the right tools, materials, and instructions. Take a read through the steps below to repair the roof joint without damaging your home and your patio.

Step 1 – Install Temporary Supports

You’ll want to make sure that the patio roof can support your weight by installing wooden posts during the repair process. Purchase 2 long pieces of wood measured at 2 by 6 inches for the height of your patio roof. Attach shorter pieces of wood to the top of the longer pieces with nails in a T-shape. This will provide more support. Take 1 post and position the top of its “T” on the underside of the roof around 1 foot from where the hole is. Have the post tilted a little bit so that it’ll fit under the patio roof. Now, use a hammer to tap the bottom of the post in the right direction until it’s vertical. Do the same for the other post, also 1 foot away from the hole but in the opposite direction.

Step 2 – Climb Up onto the Roof

Climb a ladder up onto your patio roof. Make sure you have good shoes on with a grip at the bottom for traction. Have a friend help you stabilize the ladder as you climb up. If possible and depending on the slope, try to put most of your weight on the main roof as you repair the roof joint.

Step 3 – Clean the Area

When you find the hole in the roof, thoroughly clean the area by using a brush to wipe away dirt and debris. Then, use a pressure washer for the same area. This will remove rust and expose any other potential punctures and cracks that could be contributing to the problem.

Step 4 – Seal the Leak Source

Make sure that the area is dry before you start repairs. Put on your work gloves and apply roofing cement to all of the problem areas including holes, fissures, and joints. Roofing cement can be applied with your caulking gun. Start with one coat of roofing cement. Use the putty knife to spread the roofing cement out so that it covers the leak source at least 1 inch on all sides. Let the cement dry before putting the second layer of roofing cement on the joint. This is key to prevent future leakage.

Step 5 – Complete the Process

Let the second layer dry for at least 24 hours. If there’s potential for rain, make sure to cover the area with plastic. When the repair is completed and you won’t be climbing onto the patio roof anymore, you can remove the temporary wooden supports.