12 Roof Repair Tips: Find and Fix a Leaking Roof
You can stop leaks yourself-no experience necessary. We show you how to track down and fix the most common types of roof leaks. Most leaks take only minutes to repair.
Leaky Roof Overview
How to Find Roof Leaks
A Trick for Finding Difficult Leaks
Solution for a Small Leak
Some roof leaks are tough to locate. Sometimes the water shows up at a ceiling spot distant from the leak. If your ceiling has a plastic vapor barrier between the drywall and the attic insulation, push the insulation aside and look for flow stains on the plastic. Often water runs to openings in the vapor barrier, such as at ceiling light fixtures.
The underside of the roof might have a shiner, which is a nail that missed the framing member, in this case when the carpenter nailed the roof sheathing to the rafters. If you don’t see any telltale flow marks, and since the stain is fairly small, look for flow marks on the underside of the roof. Moisture that escapes into the cold attic from the rooms below often condenses on cold nails. On a cold night, you can sometimes spot this if you climb up into your attic. Your nails will appear white because they are frozen. When the attic warms up a bit during the day, the frost melts and drips, then the nails frost up at night, and so on. Simple side-cutting pliers can be used to clip the nail.
Fix Plumbing Vent Boots
Plumbing vent boots can be all plastic, plastic and metal, or even two-piece metal units. Check plastic bases for cracks and metal bases for broken seams. Then examine the rubber boot surrounding the pipe. That can be rotted away or torn, allowing water to work its way into the house along the pipe. With any of these problems, you should buy a new vent boot to replace the old one. But if the nails at the base are missing or pulled free and the boot is in good shape, replace them with the rubber-washered screws used for metal roofing systems. You’ll find them at any home center with the rest of the screws. You’ll have to work neighboring shingles free on both sides. If you don’t have extra shingles, be careful when you remove shingles so they can be reused. Use a flat bar to separate the sealant between the layers. Then you’ll be able to drive the flat bar under the nail heads to pop out the nails.
How to Fix Roof Vents
Fix Walls and Dormers
The shingle surface is not always a point of entry for water. Wind-driven rain often enters from above the roof, particularly around windows, between corner boards and siding, and through cracks and knotholes in siding. The walls of dormer windows provide plenty of places where water can leak down and enter the roof. Old, cracked, or even missing caulk can be found between corner boards and between window edges and siding. These cracks allow water to penetrate and enter the house behind the flashing. It is possible for caulk that appears intact to fail to seal against adjacent surfaces. Make sure the area is sealed with a putty knife. Caulk that is suspect should be removed and replaced with high-quality caulk. Inspect the siding above the step flashing as well. The new siding should overlap the step flashing by at least two inches if it is cracked, rotted or missing. If you still have a leak, pull the corner boards free and check the overlapping flashing at the corner. Often, there’s old, hardened caulk where the two pieces overlap at the inside corner.
Complex Roof Problem
Fix Step Flashing
Step flashing is used along walls that intersect the roof. Each short section of flashing channels water over the shingle downhill from it. But if the flashing rusts through, or a piece comes loose, water will run right behind it, and into the house it goes. Rusted flashing needs to be replaced. That means removing shingles, prying siding loose, and then removing and replacing the step flashing. It’s that simple.
Don’t Count on Caulk!
Fix Small Holes
Leaks Around Brick Chimneys
All kinds of bad things can happen around brick chimneys. In fact, there are far too many to cover in this story. Flashing around chimneys can rust through if it’s galvanized steel, especially at the 90-degree bend at the bottom. A quick but fairly long-term fix is to simply slip new flashing under the old rusted stuff. That way any water that seeps through will be diverted. The best fix, though, is to cut a saw kerf into the mortar and install new flashing.