Finding and repairing that annoying roof leak

Finding the source of a leaking roof can of course help you know what needs repairing, and save your roof from further damage. The earlier you find it, the more likely you are to save money on repairs and reroofing. .

Shingle roofs can leak anywhere that there are cracks, splits, worn-away shingles, fissures or other spots where the material is compromised. Roof leaks are frustrating to trace because the place where water shows up inside the house is rarely directly below the leak in the roof. Water travels along rafters and beams, and it usually surfaces some distance away from the spot where it enters the house.

Start looking here:

• Valleys and around flashings at soil stacks and vents, chimneys and vertical wall joints.
• The attic during a rainstorm
• If the leak has been active for a while, you may see a discolouration in the roof sheathing or in a rafter. You may be able to trace the discolouration back to the leak source.

Once you have found the leak inside, you need to pinpoint it on the roof surface.

1. Measure from the leak in two directions — up to the roof ridge (the area where the two sloping sides of the roof meet) as well as down to the eaves and over to the side of the roof.
2. Use those measurements on the roof to find the damaged shingle.

Beware: Although it may be tempting to poke a nail up into the leak spot through the roof, don't do it. You may damage a good shingle as well as the bad one.

There will be different processes depending on what needs fixing and what your roof is made of. Look into methods of repairing wood shingles or shakes, treating wood shingles, repairing cracked asphalt shingles, repairing a flat roof and sealing flashing against walls, as necessary.