When a roof leaks, most people first suspect shingle damage. Yet, if the shingles look fine but the leak persists, then the issue could be with a different component on the roof. The following are five areas that can leak that aren't the shingles.
Skylights are very prone to leaks. The seals around the windows can fail over time. Water will also sometimes collect at the top edge of the skylight and then flow back and underneath the shingles above. New seals and installation of a barrier to route water around the skylight can solve the problem.
2. Vent Boots
There are multiple vents on top of your roof. Some vents allow hot air out of the attic, while others vent the plumbing system, kitchen range, or bathroom fan. Rubber boots seal the gap between vent and roof shingles. Over time these rubber boots can crack, crumble, or the seal may break. Replacing the boots or applying sealant around them is necessary.
3. Chimney Seams
The chimney is a common location for leaks. It is usually sealed to the roof with a combination of two-piece flashing and roofing tar. If the flashing isn't installed and sealed properly, leaks can occur. Flashing can also corrode or become damaged, and old tar may begin to crack and crumble away. The chimney must be reflashed and sealed if this occurs.
4. Roof Flashing
Flashing is also installed on other areas of certain roof styles. Complicated roofs with multiple valleys and peaks are often flashed along the valleys in order to seal the two planes of the roof surface together. This can be done with either metal flashing or rolled shingle flashing. Both can lift up, become damaged, or otherwise fail — often long before the rest of the roof has worn out. Replacing the damaged flashing with new is necessary.
Certain additions to the roof, like solar panels and satellite dishes, are often bolted in place. Generally, this is done using special bolts that have an integrated gasket designed to create a watertight seal where it enters the roofing shingle. If the bolts aren't screwed down flush or if the gasket fails, then a leak can occur at the fastener point. Damaged and poorly driven fasteners must be removed and replaced to solve the leak issue.
Contact a residential roofing service if you have a leak affecting your roof.