Ask the Architect

Dealing with roof leaks in the winter

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Q. After the last snowstorm, my roof was covered with so much snow that the ceiling was wet in several places and I’ve had to make repairs inside. Unfortunately, I have to keep the buckets on hand because the roofer told me he can’t do the correct repair in this cold weather. Is that true, and what can I do in the meantime?

A. Your roofer is right — not only because he may be concerned about appearances, but also because he probably wants to avoid more damage and to repair the leaks without replacing large areas. The winter season is the worst time to repair roofing material, since the shingles need to be flexible in order to lie down correctly and stay down. They’re too brittle to work with now.

It’s possible to heat them, and I’ve seen this done with some success, but it isn’t advisable, because there are too many weather variables. One interesting problem with putting shingles on in cold weather is that, just like other materials, they expand and contract. So when they’re nailed down, cool and contracted at this time of year, they’ll buckle when warm weather hits.

What can be done in cold weather is that the areas where leaking has been spotted can be heated with a portable heater, and tar paper or roofing felt can be worked under the shingles. Silicone sealants can also be applied around flashing (metal valleys and at side walls). Certain black plastic roofing cements can also be used, although they’re often unsightly. Just remember to make a more complete repair when the weather changes, since none of the quick fixes are long-lasting. All should be applied only according to the label or instructions.

When good weather returns, get up there and remove material, at least around the leak, and properly flash and waterproof the areas with products such as rubbery “water shield” membrane, 30-pound tar paper, roofing tar or silicone, depending on the location of the leaks. Make sure that against walls and along the roof edges, the membrane materials and flashing go up at least 12 inches higher than the roof or rain gutter. That means that on an incline, measure straight up and then horizontally across to the roof to find the distance. This method may cause an argument from the roofer that it isn’t necessary, but it works well. Also, make sure that the flashing going from under the roofing and up a side wall goes behind the sidewall finish shingles or siding, or is tamped correctly into a brick joint.

Every problem is a little different. Just like the treatment for an ailment, someone must look at your problem to pinpoint the condition and recommend a solution. Often, the damage to saturated interior construction materials is far greater than people imagine because the water spreads in all directions. Expect a larger area to need repair. Good luck.

© 2019 Monte Leeper. Readers are encouraged to send questions to yourhousedr@aol.com, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.