Find the leaks
When you’re trying to track down a leak, start by looking at the roof uphill from the stains. Roof penetrations are the first thing to look for. Items that penetrate the roof are by far the most common source of leaks. In fact, it’s rare for leaks to develop in open areas of uninterrupted shingles, even on older roofs. Penetrations can include plumbing and roof vents, chimneys, dormers or anything else that projects through the roof. They can be several feet above the leak or to either side of it.
If you have attic access, the easiest way to track down a leak is to go up there with a flashlight and look for evidence. There will be water stains, black marks or mold. But if access is a problem or you have a vaulted ceiling, you’ll have to go up onto the roof to examine the suspect(s). The photos on the following pages will show you what to look for.
If the problem still isn’t obvious, enlist a helper and go up onto the roof with a garden hose. Start low, soaking the area just above where the leak appears in the house. Isolate areas when you run the hose. For example, soak the downhill side of a chimney first, then each side, then the top on both sides. Have your helper stay inside the house waiting for the drip to appear.
Let the hose run for several minutes in one area before moving it up the roof a little farther. Tell your helper to yell when a drip becomes visible. You’ll be in the neighborhood of the leak. This process can take well over an hour, so be patient and don’t move the hose too soon. Buy your helper dinner.
Water stains can also indicate condensation or ice dam issues. Condensation problems can often be caused from bath, cooking or even dryer vents exhausting into attics rather than through the roof.
Ice dams usually happen in cold climates in the spring or on mild winter days. Have a big chunk of ice along the eaves during winter? That’s an ice dam.
Minor leaks can cause major damage
Discover a roof leak? Well, you’d better fix it, even if it doesn’t bother you much or you’re getting a new roof next year. Over time, even small leaks can lead to big problems, such as mold, rotted framing and sheathing, destroyed insulation and damaged ceilings. The flashing leak that caused this $950 repair bill was obvious from the ceiling stains for over two years. If the homeowner had dealt with it right away, the damage and subsequent repairs would have been minimal.