Composite decking mold removal

[tdemaree]

Hey guys,

I cleaned a composite deck about a month ago and used oxygenated bleach as a cleaner. I was removing black mold spots they are about the size of a dime. The client just notified me that the black spots have returned. The deck is not in a shady area, no trees to drop stuff on it. I sound like an expert! any ideas on how to remove these spots?

[PressurePros]

Bleach and a surfactant brushed on. If it came back in a month it is because you did not kill all the spores properly the first time. The only way I have found to do that, without using excessive amounts of bleach (which fades the deck) is to brush.

[Tony Szabo]

Use a 10% bleach soultion and cut it back a bit. I would first start at 50% to 50%.
Dwell time is important, but don't let dry on deck.
Ken is right you did not kill the mildew spore.

[John-Clean County PW]

We use chlorine which is 12%Bleach solution and do the same methods as Tony does above.. It looks like you didnt kill the mold spores so there back.

[Tony Szabo]

Be prepared like Ken also says it may discolor the composite boards a bit.
This happens sometimes but not all the time.

[Rick Petry]

Timothy,

This is the worst mold/mildew/fungus/dirt I have ever seen on composite. First step was just a pressure water cleaning to remove all the surface junk. Second step was 12% sodium hypochlorite knocked down to 4% with a little Dawn soap as surfactant. Let it dwell for about 20 minutes and lightly pressure wash it off.

Disregard the smoke, I have a bad habit.

[schrec]

12% 50/50 with some soap, no pressure.

We offer a product that makes the mildew not come back for two years. We have a lot of it and its $130 a gal, mixes 26 to 1. Any one want some call me 784 0961. Its good stuff.

[Beth n Rod]

I'll add to what Tony and Ken said, if it is farther into the substrate than the chems can migrate to work, it will come back again. It is possible to have it pretty far into the board. That is one problem with composites....

Beth

[AlwaysAqua]

Timothy,

This is the worst mold/mildew/fungus/dirt I have ever seen on composite. First step was just a pressure water cleaning to remove all the surface junk. Second step was 12% sodium hypochlorite knocked down to 4% with a little Dawn soap as surfactant. Let it dwell for about 20 minutes and lightly pressure wash it off.

Disregard the smoke, I have a bad habit.

You need to sell that photo to TAPPS. They would have a field day searching for ghosts lol.

[Tony Szabo]

Just speaking from experience here. You should not pressure wash composite decks.
You are forcing and driving to much water in the composite boards and the water does not excape like water does in wood. You are dealing with plastic and saw dust here and the procedures are much much different than every day wood care.

Now, when you pressure wash composite I bet you will have mildew return fairly quick, because the wood (saw dust) can not dry out quickly enough before mildew spors start growing in the substrate of the composite boards. We use garden hose type pressure only and scrub.

Just giving advise of our 400 plus composite deck we have serviced in the past, and extensive research with the Trex company Tech People.

Good Luck

[The Mold Expert]

You can try Microban Disinfectant Mold Killer. It's EPA Registered and used by mold experts. These two companies do a great job with Mold Removal, Mold Remediation, Mold Testing, Mold Inspection, Mold Abatement, Mold Cleanup

http://www.absolutelyspotless.us

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[PSIPressure]

bleach is king