How to Clean a Black Stain on a Painted Aluminum Gutter
LESLIE: We’ve got Terri in Pennsylvania on the line who’s got a gutter issue. Tell us what’s going on.
TERRI: I have white aluminum gutters and on the gutters that face the southern exposure, the part of the gutter that faces out is turning black and there’s like – where the water runs off it, it’s like a dark gray and just water drips all along the face of the gutter.
TOM: Right. So does it seem like the gutters are overflowing and the water is coming over the top and getting these sort of drip marks? Is that what’s going on?
TERRI: Well, yeah. I have what’s called a “gutter insert” to keep the leaves out. And I know that – well, I’m pretty sure that that’s not causing it, because I had the same problem when I lived on Long Island. And it was only the gutters that faced south and on Long Island, we had a white aluminum top to the gutter to keep the leaves out?
TOM: Right. Mm-hmm.
TERRI: And then the water would roll off of that and then go into the – it would be caught into the gutter. So, it’s a different type of leaf system but I’m still having the same black drip.
TOM: Right. OK. So, first of all, I would make sure that the gutters are not blocked and that water isn’t backing up and overflowing that particular gutter, so that – because that water rolling over the top of it, it can get behind it, it can rot out your fascia.
The dark stains are probably from the water and tree sap and everything else that gets into those gutters. The gutters also fade quite easily; the paint wears off and fades quite easily. So I don’t think it’s a stain that you’re going to actually have to be able to clean. I think what you’re going to end up having to do here, Terri, is repaint those gutters.
So what I would do is I would wash them down with a trisodium phosphate, get as much of that gunk off. Then I would prime them and I would paint them again. But just – but do make sure that they’re not clogged, because that could be leading to the problem.
TERRI: But yeah – no, they’re definitely not clogged. And I tried scrubbing it – the ones that aren’t on the second story, where it’s worse. The ones that are on the first story, I tried cleaning it with a Fantastik and it bleeds into the stain a little bit but I didn’t realize that the aluminum gutters – was it like a hydrostatic or electrostatic painting process?
TOM: What happens is – and you’ll see this: if you take the gutter and you wipe your hand over it, you’ll probably get some white paint that will come off. It oxidizes because it’s exposed to UV. And so then the paint doesn’t tend to last more than maybe 10 years or so on aluminum gutters.
So I think, though, if you clean off as much of this thing as you can, prime it and paint it, it’ll look great.
TERRI: Alright. Great. I’ll give it a try.
TOM: Terri, thanks so much for calling us at 888-MONEY-PIT.