Last winter here in Massachusetts we had several significant snowstorms. During a period of a few storms in a row, a lot of snow piled on the roof. Despite raking most of it off, my bedroom ceiling started leaking-from the edge of the outside wall in about 4 feet. It spread about 6 feet across. The house is a ranch and the roof was only 2 1/2 years old. I wiped up the water- it only dripped a little, but the stain remains. I looked up in the attic, but couldn’t find any noticeable leak or moisture up there. As far as attic insulation goes- there is no vapor barrier and the insulation is old blown in newspaper.
No pink stuff. We had central air conditioning installed 2 1/2 years ago- the airhandling unit and a bunch of flexible ductwork take up much of the attic.
I am worried that we may have a reoccurance again this year.
Questions: What was the cause of the leak? Is the attic insulated enough? Could the airconditioning install have messed up the effectiveness of the attic insulation?
Could the roofer have messed up? The general contractor who hired the roofer told me that ice and water shield was laid under the shingles as is standard. Wouldn’t that have made a rubbery seal, preventing ice/water from penetrating the roof and going into the attic then the ceiling? After 2 1/2 years should the roofer still warranty his work? How about the general contractor?
Lots of questions, I know. I hope that I have provided enough info. for someone to help.
Thank you.
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While it could be a roof leak, it could also be an air leak.
If bulk warm moist air leaks into the attic space, it will condense on cold surfaces, like your roof deck, then drip down.
The air could come from leaky ducts, or leaks through the attic plane.
Leaks through the attic plane can be from any number of things, including; leaky hatch, unsealed pot lights, open stud bays, mechnicals penetrations, chimney chases, ...
Most likely, based on your description, this was caused by an "ice dam". This occurs when heat inside the house heats the snow on the roof and melts it. But towards the edge of the house the roof isn't as warm, and the meltwater refreezes, creating a "dam" that can hold several inches of water on the roof. This water then creeps back under the shingles and leaks through gaps in the sheathing.
If you didn't disturb the cellulose insulation you can usually see driplines in it where water dripped from above.
There are two solutions to this problem. When reroofing you can have an "ice and water shield" installed on the roof. This is a rubber membrane that goes under the shingles and runs from the edge of the roof up for several feet. It doesn't prevent the ice dam, but it keeps most of the water from leaking through the roof. (In your case the roofer may have installed only 3 feet of membrane when you actually need 5-6 feet to be effective. Or the membrane may be leaking -- it's not perfect and should not be depended upon to prevent leaks in spite of bad ice damming.)
The other solution is to lower the temperature in the attic, so that the snow on the roof doesn't melt. This is done with a combination of sealing and ventillation -- seal air leaks into the attic from below, and add air vents at the eaves and along the peak of the roof to let any heat out.
Note that a dryer vent or bathroom vent that terminates in the attic rather than continuing to the outside can be a major problem. It not only adds heat to the attic but also introduces humidity there, which can then condense and directly cause water damage.
During the winter ice dams can sometimes be prevented by using a "snow rake" to remove snow from the edge of the house, reaching up the roof at least two feet beyond the edge of the house (which may be, eg, four feet up the roof if you have a two-foot overhang).
Sounds like Ice damnig to me as well.
I've seen this alot. The manufacturers tell you to lay this membrane on the deck only. The problem I see is Ice being built up in the gutter and getting over the fascia board. If the house has an overhang then most leaks show in the 2nd floor wall or ceiling of the 1rst floor. For years now we've been folding the I&W over the fascia and reattatching the gutter. Haven't had 1 callback in 6 years! I have attatched a pic to hopefully show you what I am talking about.