The best methods of repairing a leaking patio roof depend on several factors, including the type of roofing material used, and the location and size of the leak. Some leaks can be fixed using sealant or standard methods of repairing the specific material. If a leak is too large to repair, it might be necessary to replace a section of the roof to resolve the problem.
Identify the location of the leak. Leaks in wooden roofs are commonly caused by a gap between the panels, which move during expansion and contraction.
Fill a caulking gun with a watertight polyurethane or oil-based sealant and hold it at an angle to insert the product directly into the gap. For a gap of 1 inch or less, caulking or sealant is the best method of repair.
Apply the sealant in a smooth bead all the way along the gap. Press it in with a putty knife if it starts to ooze outward.
Check the joints of a corrugated metal or plastic roof. The sheets are commonly overlapped at the joints, and deterioration of the material at the location of the bolts holding the panels in place can cause leaks.
Use a polyurethane sealant and apply it around the boltholes on the underside of the panels and allow to dry. The premixed spray foam sells in DIY kits with two dispensing units and comprises flexible, open-cell polyurethane that resembles balloon rubber.
Paint over the sealant with water-resistant paint or varnish. This will help it to blend in with the roof panels and protect it from degradation.
Find the area where the fiberglass is leaking and determine whether the material is cracked. Fiberglass is a lightweight, translucent material that develops cracks easily.
Clean the fiberglass around the crack thoroughly with acetone. Roughen the area with 200-grit sandpaper.
Soften a cut-to-size patch of fiberglass "matting" with resin and paste it over the crack. Allow to dry, then sand it down level with the surface of the roof and apply a coat of clear gel to the area.
Fix a tear in a vinyl patio awning by attaching a patch of vinyl with similar size and weight characteristics as the awning.
Spread vinyl glue on both surfaces and allow it to dry, then position the patch over the torn area. The two surfaces should bond immediately.
Press down firmly on the patch to remove any air bubbles in the glue.