It is just after the rains and there are a few patches of moisture along the walls and puddles of water on the floor. The roof has started to leak. Now what? Well, it needs maintenance and maybe some expert advice. The first thing is to determine the source of the leak and go about the repair. The method to determine the source of leak in the house is simple. The leaky spot is often further up on the roof than the location of the drip unless you have roof trusses. With trusses, the maze of lumber makes it tough to find. Next time it leaks during a storm, play detective. Take a roll of paper towels, a flashlight and a tape measure up into the attic. Tear off a paper towel and touch it to all the lumber near and above the leaky spot.
Although you may not be able to see the water trickling down a truss member, you will see a damp spot on the paper. Use this paper towel method to track the water leak to its highest point inside the attic. If you are lucky enough to pinpoint the leaky spot, measure its location from the side and top of the underside of the roof. You will use these measurements to locate the spot on top of the roof. The next step is to start with the repair.
Most shingle repair, be it asphalt, wood or slate, follows the same rules and steps; Separate and isolate the bad shingle from those around it, remove the nails, slide out the bad shingle, and replace. Wood shingles, shakes and slate require that you cut the nails with a hacksaw rather than remove them, and re-nail in a relatively exposed spot; but in all cases, you use roof cement to seal those nail heads. Even if a damaged shingle is not conveniently in the field, but lives instead in a peak, valley or vent, the procedure remains basically the same: isolate, detach, remove, replace, reseal.
One place where extra caution must be used is at any shingle/flashing interface. For instance, a shingle along a valley can’t be nailed too close to the flashing for fear of puncturing it; use roofing cement at the flashing end, and nails at the other end. If a shingle goes under a piece of step (sometimes called lea flashing, be extra careful not to disturb the flashing at all. You can enlarge a small leak to a major waterfall here. Wood shingles can last between 15 and 40 years. Their durability depends on your climate, their exposure to the weather, and the slope of your roof. As a rule, the steeper a roof, the longer the material will last because water won’t pool on it and ice and snow won’t accumulate and damage the wood. If your roof is leaking, or you suspect you have cracked or damaged shingles due to a recent severe storm, check your roof for curled, broken, or split shingles. Wind and rain can erode shingles and cause them to lift from the roof. Check for damaged shingles or go in the attic and look for signs of water–either dampness or stains. If only a few shingles are damaged, repair or replace them. If many shingles are broken, you may need to replace the entire roof.
You have attempted the repairs yourself and after a few days you find that the shingle still leaks. Then what is the next course of action? Besides calling for the roofer there is no other choice. So just pick up the phone and call the more experienced roofer.