Get tips on cleaning and treating a moldy deck. Mold can be easily cleaned with an oxidizing solution and mild abrasion. Finish by sealing your deck with a stain.
LESLIE: Bob in Alaska has a question about mold on a deck. What can we do for you today?
BOB: Yeah, I’ve got a deck. It’s about 22x14 and it’s about 18 inches off the ground on the north side of the house. This year, I believe it was – it’s four years old – we started noticing some green spots on it.
TOM: Now, Bob, I see on the screen that you’re from Wasilla, Alaska?
TOM: Can you see Russia from your deck? (Bob and Leslie laugh)
BOB: No, not quite.
TOM: Well, I mean they probably can see you so this could be, in fact, a matter of national pride. We don’t want them to think that the Americans don’t take care of their decks. Well, listen …
BOB: Maybe they’re shooting mold over here, huh? (Leslie chuckles)
TOM: (laughing) Maybe they are. Maybe they are.
BOB: What’s the best way to get rid of this stuff?
TOM: Alright, here’s what you need to do. First of all, you’re going to need to clean that deck now with a mildicide solution. Now you can use something as simple as bleach and water. You can use OxiClean
; good product, does the job. You can use a product called Jomax
. These are all mildicides and the trick here is how you apply it. You need to actually wash the deck down, let that stuff sit for 10, 15, 20 minutes. That’s how it goes to work and kills all of that mildew that’s forming on the deck. Then a little light abrasion – sort of a stiff working at it with a broom or a scrub brush, loosen it up, and then a good rinsing. And that’s something you’re going to have to repeat in your neck of the woods probably every six months, I would think; maybe once in the beginning of the season, once towards the end of the season to keep it looking good.
Now, do you have any shade on that side of the deck? Are you getting a lot of sun?
BOB: Yes, it’s the north side of the house; that is the shady side of the house.
TOM: Yeah, and you know that’s part of the problem. The more sun you get on that, the less the moss and the mildew is going to grow.
TOM: So if you can thin out the tree just a little bit to allow a little more sunshine there, that will actually help a lot.
BOB: What about the underside of the deck? You need to hit that with it, too?
TOM: No, you don’t have to worry about that; just the surface.
BOB: OK. And do any good to put any kind – can you put any kind of a sealer on it when you’re done cleaning it?
TOM: You can. You can put a sealer on it. What we would recommend for that is a solid-color stain. Has there ever been anything on this at all?
BOB: Well, it’s deck wood. It’s a brown, treated deck wood.
TOM: Right. So you …
BOB: No, there has been nothing put on it.
TOM: Alright, so what you might want to think about is using a solid stain
. Now, stains come in semi-transparent, clear and solid color. Solid color is going to do a much better job because it’s got more pigment in it. You’ll still see the grain that comes through it. It’s got some mildicide as well and it’ll look a lot better.
TOM: Alright, Bob?
BOB: Well, won’t have to do it til next spring because it’s covered with about four inches of snow right now as of today.
TOM: Alright, well you make sure that when that snow melts that the Russkis have something good-looking to stare at, OK? (Leslie chuckles)
BOB: Yeah. OK. Hey, thanks a lot.
TOM: You’re welcome, Bob. Thanks so much for calling us at 1-888-MONEY-PIT.