Unsightly water marks on ceilings are a sure sign of a leaking roof that needs immediate attention. Delays in fixing a leaking roof can turn a small problem into a big one. Over time, a leaking roof will cause water damage to several structures in the house, resulting in high repair costs.
Detecting and locating a leak
The surest indicator of a leaking roof is water marks on the ceilings and walls. The leak is not always directly above the water mark, so it takes a little effort to locate the source.
- For homes with accessible attics, checking the roof for mould, black marks or water stains is a simple way of finding a leak.
- For homes with inaccessible attics or vaulted ceilings, the leak is found by climbing onto the roof and inspecting it. The most likely sources of leaks are the structures that project from the house and through the roof. We should check the chimneys, dormers and plumbing vents for cracks and loose seals.
- While on the roof, we should also check for broken, missing or cracked shingles and check if the damage extends to the underlying structures.
- If the leak is not found by visual inspection, it can be found by soaking areas close to the water mark with water to see if the water will reach the ceiling. This is a two-person job. One person goes on the roof with a hose and soaks the area above the water mark with water while the other checks for dripping water inside the house. If no leak is found, soak the spot to the left of the water mark and check for leakage, if no leak is found, then soak the spot to the right of the water mark. If the leak remains undetected, try the area uphill of the watermark and repeat the process until the leak is found.
- Some leaks are very small and very well hidden. They happen in houses where the ceiling has a plastic vapor barrier between the attic insulation and the wall. Such leaks can be found by looking for flow stains on the plastic barrier. If no flow stains are found on the plastic, the source of the leak is probably a protruding nail on the underside of the roof. In cold weather, moisture freezes onto the nail and when the temperature rises, the water melts and finds its way to the ceiling. Removing the leak caused by nails is easy. Simply clip the nail with a suitable pair of pliers.
- Leaks from plumbing vents can be caused by a number of faults. If the cause is a loose base, all we need to do is re-attach the base with screws that come with rubber washers. If the cause is a worn rubber boot or a cracked base, we replace the damaged parts.
- If the roof vent’s housing has a crack or a broken seam, replacing the housing of the vent is the permanent solution. Using sealant on the cracks is temporary.
- Leaks caused by dormers mostly happen because of cracks in the siding or gaps between the siding and the corner boards. Cracked siding must be replaced, there’s no way around it. The replacement siding should overlap the flashing by a couple of inches.
- Gaps between the siding and the corner boards can be repaired by re-applying caulk to seal all spaces that allow water to seep through.
- If the leak is caused by cracks or holes in shingles from old mounting holes, the affected shingles should be replaced.
- Faulty flashing can cause large leaks. If the flashing next to a wall or chimney comes loose, nailing it back stops the leak. If the flashing is rusted, it will have to be replaced.
A stitch in time
The most important aspect of dealing with leaking roofs is the timing. The sooner the problem is sorted out, the less it costs us. All it takes is prompt action, some time and some effort. For our homes, though, the effort is well worth it.