I’ve had a persistent leak for two years and can’t find the source. It comes in where the wall meets the ceiling. I’ve caulked all around, had the flashing around all the penetrations inspected, and recently had siding and gutters replaced, during which we inspected the flashing and added a better drip edge, all to no avail. My contractor tells me the roof pitch may just be too shallow for shingles to work well. He estimates it at 2/12.
I had the roof replaced in 2003 because it leaking then, which at the time I attributed to skylights that I had removed. I just found the original contract for the earlier roof replacement, and it records the pitch as 3/12 (actually it says 3/5 in 12 but I assume that is referring to a steeper part of the roof that was also involved in that project.) That contractor never told me that shingles might not be the best choice.
My questions are:
Does it sound likely to you that replacing the shingles with a material more suitable for a low-pitch roof could resolve the leak?
Do I have any case for asking the original contractor to do the work or cover the cost of another company doing it? (It has caused considerable interior damage as well.)
Michael, Asphalt shingles can be installed when the roof pitch is 3/12 or greater so you are definitely at that border line area. To help prevent leaks though, I typically recommend that Ice & Water Shield be installed across the entire roof (not just the roof edge) when the slope is so shallow. In fact in areas that are subject to extreme weather like the hurricane coast, for example, we recommend the same thing.
So in answer to your first question, replacing the roof may help but only if you add an additional layer of Ice and Water Shield under the asphalt shingles.
Going after the original contractor will be difficult. Assuming the contractor won’t accept responsibility and you need to sue, you may need to hire and expert witness to testify that the job was done wrong (assuming it was) as well as an attorney. This costs may exceed the cost of the roof replacement.
The best thing might be to do some testing to try and narrow down the exact source of the leak. One way to do this might be to use a garden hose to run water down the roof right over the leak area to see if you can pinpoint the spot that leaks. You might also consider hiring a professional home inspector to help you diagnose the cause of the roof leak. For a relatively small fee, these folks can give you an expert opinion and may help you save time by getting to the root of the problem quickly.
Well, I think it’s closer to 2/12 regardless of what the original contract says. Those numbers meant nothing to me at the time, but I’ve become more educated since then.
My plan is not to replace it with shingles but with a material more suitable for near-flat roofs. I have had several people out to try to find the source and no one can — penetrations have been reflashed, drip edge has been replaced, nothing helps and no one can find anything specific. It seems likely to me that the underlayment has developed some tears or gaps and water is backing up under the shingles somewhere.