Drip, drop, plop! If you hear these torturous sounds in your house, you probably have one of the more frustrating types of maintenance problems – a roof leak. In spite of modern construction techniques and improved materials, water stills finds its way into buildings. Responding to the force of gravity, water seeks out the shortest possible route to the ocean. Unfortunately, this route sometimes leads through your house.

Poor construction is the cause of many preventable roof leaks. Some common mistakes are omitting eave protection, not gluing the shingle tabs, installing the bottom row of shingles flush with the fascia board and improperly installing flashings. However, even the best roofing job fails after years of exposure to the elements. Knowing the early signs of shingle failure prevents leaks due to age and avoids having to replace other building components damaged by unwelcome water. Unchecked leaks allow moisture to build up in wood structural members, which fosters the growth of another destructive force – mold.

Inspect your roof at least once a year and check for missing, curled or cracked shingles. Minor deformations may be fixed with roofing cement, but replace severely warped shingles as soon as possible. Roofing work is best done on warm days when the shingles are more flexible and less brittle. Use only galvanized nails and seal the heads with roofing cement.

If you have a brick chimney, take a close look at the flashing inserted into the mortar joints. Since it is the highest point on a house, the chimney receives the most exposure to wind and rain, which puts stress on the mortar joints. Check for cracked, loose or crumbling mortar and corroded flashing.

The most aggravating aspect of roof leaks is that their source is not always readily apparent. The initial entry point for the water is often remote from the area of the ceiling where the drip appears. When this is the case, it’s time to play detective.

Climb into the attic with a flashlight and measuring tape. Look for water stains on the underside of the roof deck and trace the path back to the entry point. Also, turn off the flashlight and check for pinholes of light where water may be entering.

Measure the distance from the leak to two reference points, such as a plumbing vent, chimney, ridge or roof intersection. This helps locate the leak when you climb onto the roof. Alternatively, drive a small nail up through the roof at the leak so it can be easily found from the rooftop.

Most leaks near the lower part of the roof are due to lack of eave protection. In winter, snow accumulates on the overhang forming an ice dam, because it is colder there than over the main roof, where rising warm interior air melts the snow. Water from melting snow higher on the roof becomes trapped behind the ice dam and backs up under the shingles through capillary action.

When the temperature falls, water under the shingles freezes and expands, lifting and deforming the shingles, making the situation even worse. During the next thaw, water seeps below the shingles to the plywood roof deck, eventually dripping into the attic and rooms below.

Two types of materials are recommended for eave protection: Type S (smooth surface) roll roofing, or 2 layers of 15 lb. roofing felt. The coverage must extend from the roof edge to a point at least 12″ beyond the inside face of the exterior wall, and have an overall minimum width of 36″. Confirm the full requirements with your local building code.

Roof leaks are particularly destructive, since water entering there damages everything below it, including insulation, finishes, furniture, appliances and grand pianos. Keep your roof in good shape, so your buckets will stay in the closet where they belong!