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suggi1

08:20PM | 09/27/09
Member Since: 09/03/07
32 lifetime posts
Bvroofing
Could you tell me what to do about black roof stain. Never had it before and a lot of houses seem to have it this year. Luckily we do not have a lot so far. Massachusetts had a very wet and humid spring and summer this year and don't know if that has something to do with it.

I have a handyman that cleans my gutters and puts a layer of tar around the stackpipes in November. (The roof is in good shape but there was a crack in the tar around the stackpipe that got into the attic but since we tar it every year there has been no leaks.

I would prefer something environmentally friendly if possible and hopefully he could do this. I believe he also does some roof repair.

I read on the internet never to power wash your asphalt roof. Is this true and if so how do you apply whatever to clean the asphalt roof shingles.

Thank you.

OddBall

05:41AM | 10/01/09
Member Since: 11/10/06
138 lifetime posts
The staining you`re describing sounds like mildew, it grows under the headlap of each row of shingles. It is in ideal conditions to grow when water is allowed to travel along the headlap. The water enters either through a flashing problem on a wall or chimney or pipe ect. ect., or from the edges. This entry is due to the roofing not being straight or even level.The water travels along the headlap and drains at joints or from under the shingle at places of least resistance such as the space between the self seal strip. When the water exits, it deposits excretions, oil from the shingle, growth. That`s the stain. It is on a mircro scale and you can lighten it with a bleach solution but it is not totally removeable.

Never power wash your roof. Use a SOFT bristle push broom or like me, a 4 inch paint brush. SOFT SOFT bristles only or you`ll scrape off granuals.

There should be NO tar around your pipe. The proper size flange, correctly roofed, with a silicon caulk ring aroud the collar for back-up, will last the life of your roof with no need for tar. Tar is not an extierior flashing. A lead pack joint too close to the roof for a flange or old type packed flange (break it off with 16 ounce hammer) can easily be removed or cut and lowered inside to provide the modern flage style to fit.

This staining almost always happens when there are more than one layer of roofing on your home.

Posting photos` helps guys like me give more accurate proffessional advice. BTW, I don`t know how to post photos` !!


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