Emergency roof repairs in winter
Q: October’s stormy weather seems to have done it for my roof: During the last big storm, the roof upstairs started leaking. I climbed into the attic crawlspace but could not locate the source of the leak, although there appears to be some moisture on the bricks of the chimney. Could it be that my chimney is leaking? — Bob S., Lowell, Mass.
A: My first guess would be that the chimney flashing — shaped metal sheets interwoven with the roof shingling — is damaged and that water is leaking in at the damaged point. Flashing covers the gaps at roof joints and outlets (like chimneys and vent stacks) and is the first line of defense against water leakage. The metal — aluminum or copper — is very durable, but damage from debris strikes, or from small critters (like raccoons) tugging away surrounding shingles, can take its toll.
Damage to the chimney itself is possible, if the outside stack hasn’t been checked in a few years, or if the stack took a direct hit from a large piece of debris during recent storms. A damaged chimney — especially an active one (venting fireplace or heater gases) — is an emergency that should be addressed by professionals, and quickly.
Hopefully, the former problem is the issue. But you just won’t know until you can get onto the roof and take a look, and if it’s really windy or snowy, going up top is dangerous. I recommend bringing a partner along to steady the ladder as you climb, and hold the safety rope taut as you make your way to the suspect area. If you can’t get a helper or don’t have safety equipment, call a professional. It’s always better to pay for an inspection than for a hospital visit.
Damaged chimney flashing really should be replaced rather than patched up and nailed back into place. But in winter, you may not have many options. You can make a temporary repair using roofing caulk or weather-resistant sealant, but the next big storm might blow that out again.
If the weather report predicts a few sunny, fairly warm days, take advantage of them to replace the flashing (and surrounding shingles if damaged) with matching metal, using pliers and aviation snips to bend and size the metal properly. Copy the other flashing’s interwoven pattern, mortar in place, and layer the new shingles over the replacement.
Home Tip
Act quickly to minimize damage from ceiling leaks: place a container underneath, then punch a small hole where the drip is, using a screwdriver or awl, to allow pooled water to drain. Don’t patch the hole until the source of the leak has been located and repaired.