Thread: Damp areas on roof

It rained and sleeted for a short time about 16-18 hours before this inspection.
There were two conspicuously wet areas on an otherwise dry roof. One was at the eave of the garage roof and the second was above and between 2 skylights.

1. The house is not occupied
2. Power, water, heat were off.
3. There was no evidence of leaks in attics near where these damp spots are located
4. There was no evidence of leaking inside the skylight wells.
5) The roof is near the end of its useful life and will require replacement in the near future

I've not noticed damp areas like this on an otherwise dry clean roof before. I was wondering if anyone had experience with this condition and had a viable explanation for its cause.

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Sleet piled up (see gutter) and kept the roof wet as it melted.

Originally Posted by Jim Luttrall

Sleet piled up (see gutter) and kept the roof wet as it melted.

What's in the gutter is left over snow from a couple of weeks ago on top of leaves. There wasn't enough sleet to build up on anything. The gutter was clear under most of that damp area. Thanks though.

Originally Posted by Stuart Brooks

It rained and sleeted for a short time about 16-18 hours before this inspection.
There were two conspicuously wet areas on an otherwise dry roof. One was at the eave of the garage roof and the second was above and between 2 skylights.

1. The house is not occupied
2. Power, water, heat were off.
3. There was no evidence of leaks in attics near where these damp spots are located
4. There was no evidence of leaking inside the skylight wells.
5) The roof is near the end of its useful life and will require replacement in the near future

I've not noticed damp areas like this on an otherwise dry clean roof before. I was wondering if anyone had experience with this condition and had a viable explanation for its cause.

Stuart,

Can't tell you about the area adjacent to the skylight, but it looks like the gutter has lifted the shingles at the eaves, which would tend to allow water to pool. Around here, that would result in damaged eaves; however, an ice shield might prevent damage.

I was wondering if anyone had experience with this condition

I do not.

....and had a viable explanation for its cause.

No, but....

The wet area at the eave looks different than the other (at least in the pics). The shingles appear to flatten out at the gutter and may have let the water pool up and keep the bottom run of shingles wet.

The big area looks like a stain from some sort sealer that spilled or leached onto the roof from the pipe collar and skylight. This film keeps the moisture from drying out similar to an oil stain on concrete, yes I know on the concrete is not a great analogy, but that is the best I could come up with.

If your not sure , call it out for further evaluations by a licensed roofing company. Protect your e and o.

By looking at the pictures, and reading the weather description, I would deduce that the water coming down between the skylights is likely the slow melt (as there is still sleet in the gutter) of the sleet which is tucked in behind the skylights out of the sun. With nothing else on in the house it is unlikely that it is anything out of the ordinary.

Frank Suchodolski, RRO

Hey Jim,
It looks like water was trapped between the skylight flashings and the shingles. Water was weeping out from behind the steps or the apron behind the skylights. It's hard to tell if there was roof cement on the pipe boot or not. If so it could have been trapped in there also. Was it warming up after a cold night of freezing temps? That would be a reasonable explanation. Ross