Most roof leaks come from a failure of the flashing. The most common flashing to fail is the one around the chimney or a skylight. It is also possible the boot on the vent pipes or other roof protrusions has failed.
If the flashing is tar, special attention should be paid to it every spring and fall, the tar tends to dry out and crack allowing water to penetrate the roof.
- Step flashing on a chimney may be loose where it is cemented into the brickwork. It is best to have the mortar joint repaired. In some cases silicone may have been used in the joint.
- Many chimneys are flashed using tar and such chimneys must be re-tarred every couple of years. After a very hot summer the tar will probably have developed cracks that need sealing.
- Check the top end of any leaking skylight and caulk any seams in the flashing. Inspect the seal around the glass and caulk with silicone if necessary.
- If the rubber boot around vent pipes is failing, it should be replaced. For a temporary repair, try caulking the boot with silicone.
- A leaking roof valley should be professionally repaired.
- Nail heads that come up through the shingle should be hammered down and sealed with tar. Nail heads pushing up a shingle should also be fixed immediately. Place the flat end of a pry bar on the nail head while holding the other end. Then, hammer on the pry bar and it will push the nail back in. Do not hammer on the shingle to drive in the nail.
NOTE: Roof leaks should be repaired immediately before the structure of the home is affected. A roof leak can cause very expensive damage to a home in a short length of time.