How to Clean Shingle Stains

LESLIE: Now we’re going to give out some cleaning advice for Jeff in Texas. Tell us what’s going on at your house.

JEFF: Well, my mother – her roof has composition shingles on it with black stains on it. I’m trying to find a way to safely remove the black stains without harming the shingle or the vegetation down underneath with any kind of a …

TOM: Well, probably what you’re going to need to do – now is this a pitched roof? Is it very steep? Can you walk on the roof?

JEFF: You can walk on it …

TOM: Here’s what I suggest you do. The first thing you want to do is wet the roof down and you want to apply a solution of Jomax to it. It’s a cleaner that works very well to clean moss off of roofs.

LESLIE: What about for the vegetation? The plants around? Should he cover them up?

TOM: You have to cover it with tarps. You’re going to have to cover it with tarps; unless, of course, you have a gutter system and that you can collect any runoff from this. But if you cover them then they’ll be protected and good enough for this application. And once you put the solution of Jomax down you want to wait 15 or 20 minutes for it to really do its work. Then you want to follow up with a stiff, bristle brush. You can use like a floor brush.

LESLIE: And be really, really careful, Jeff, because this stuff makes the whole surface really slick. So you want to make sure because it’s really – it’s a cleanser. It’s going to be sudsy, so be careful.

TOM: Yeah, like start from the bottom and work up. Don’t start from the top and work down where all the soap is running under your feet.

Now, once you get it clean there may be some things that you can do to avoid this moss growing back the next time.

LESLIE: Yeah, you can actually install a nickel or a copper ridge vent. And when this sits on the ridge of your roof, as it rains it’s going to actually let some of the minerals within the nickel or the copper and that’s going to run down your roof and you’ll see clean spots. If you ever see copper flashing around a chimney or somewhere on a roof, you’ll see that there’s streaks of cleanliness coming down from it. And that’s some sort of natural reaction from the rainwater and the nickel or the copper. So that’ll be a natural defense and something you don’t ever have to think about going back up there and fixing.