How to Clean Moss From Shingles
LESLIE: Next up, we’re going to take a cleaning question from Len in North Carolina who has moss growing on some fiberglass shingles.
Len, where is this occurring?
LEN: It’s on the west and north side of the house. The house sits north and south.
LEN: And it has like a step-down. You have like a 60-foot section and then it steps down. Right where that steps down and extending out maybe three or four feet, it is really getting bad. The moss is actually beginning to push the shingles up.
TOM: Oh boy, that’s not good. Is that a fairly shady area for you, Len?
LEN: Yes it is.
TOM: Yeah. That’s typical because the less sun that can get there, the more the moss is going to grow. And so there’s a couple of ways to attempt this. First of all, if there are any overhanging trees, you can get a little more light on that roof. It’s going to help you avoid this problem in the future.
The next thing you want to do is you need to wash that down with a bleach solution because you need to kill that moss and get it off of there. And the third thing that you could do is above it, where the water runs down across that roof area, if you put a strip of copper or nickel flashing on the roof, like wrap it over the ridge, some of that metal will release into the rain water and then acts as a mildicide as it runs down your roof and keeps it clean.
LEN: Alright. What would the solution – what is the mixture?
TOM: Well, if you use straight bleach, you’re going to probably want to use a fairly strong solution; I would say at least one part bleach, two parts water. Another way to go would be with an oxygenated bleach, which works very well because as the oxygen gets exposed to sunlight, it really activates.
TOM: And there are lots of products available, in home centers and hardware stores, that can help you do that. But most importantly, be very, very careful because you don’t want to be spraying any slippery bleach solutions up there while you’re standing on your roof.
TOM: OK, Len?
LEN: Thank you very much.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.