Need help with this one. My guy downstreamed our house wash on deck which is SH elemonator and water. Looks like this after.
This is after pressure from white tip. Just one spot
How can I correct this?
I washed a deck last summer like this. I didn’t use SH just pressure washer at a distance. I didn’t get any discoloration.
There is a youtube video showing this can happen to some composite decks with SH, and to do a test first…sorry…but there is a product (that I have NEVER used) that says it can fix it Messmer’s Composite Deck Finish |
1 Like
If you didn’t pre-wet the deck before applying the house wash mix then it probably is stained. Those look like clean spots to me. Might try re-cleaning with a stronger HW mix to even it out.
5 Likes
I would try out some oxallic acid on it. Mix it like you’re brightening a wood deck (because of the high natural wood content of older trex, that’s basically what you’re looking to do)
1 Like
The spots disappear when it dries. But it now looks like a yellow deck. I think it was grey to begin with but it was so dirty it was hard to say.
That’s under the deck.
It can bleach but with a high %. I had a trex deck that stained from leaving my x Jet Pail on it that I had spilled SH. I’ve had that happen before ( what your talking about) my theory is that it’s actually where mold and algae spores were growing and has removed the surface of the finish.
Again just my theory
1 Like
Not visible until you clean and remove those spores
1 Like
This is that old porous Trex material that turns black. I think the decks have been lightened by the sun. I used the same mix on top of the deck as I did on the bottom and the bottom is still a darker color. I’m guessing because it never sees any sun. I’ve brushed straight chlorine on a deck before and didn’t see any change in color other than the mold and dirt coming off. Well if the owner complains I will have some explaining to do. They bought the house 2 years ago and I doubt the decks have been washed in at least five years. They have never seen them clean.
1 Like
From Everett Abrams:
First we nee to differentiate between older generations of the composites versus newer generations. The new generations of composites like Trex are encapsulated. This is a hard covering shell that is on top and somewhat around the sides. It is not fully encapsulated so that it will breathe and not retain moisture. The comparison here is the shell is like the coating on a golf ball. This coating allows for the “current” recommendation of 3100psi to “clean” with. Now for those who do this for a living we know that “pressure” does not clean and this is somewhat irresponsible on their behalf. A cleaning solution of sodium hypochlorite, detergent, and water will work therefore needing less pressure. In summary they finally got the product right and now have a 25 year guarantee. The recommended psi is overkill though.
Now in regards to older Trex and composites, you must first know the make up of the product and how it was manufactured before making some of the previous comments. Trex was made with recyclables and about 50% wood. The wood used was Red Oak which they thought would give it durability. It was recommended to them that even it were 1% wood it would need to be sealed by the AHJ’s. If anyone has ever cleaned up leaf stains, specifically oak leaf stain you know how hard and deep the black staining goes. The product make up was also conducive to mold and mildew growth so it wasn’t long before this material had black spotting.
These black spots were two fold. NOT ONE, as many here would have you think. Trex, eventually by though own admission, developed a two step product to clean the older generation composites called Corte Clean. First step was sodium percarbonte to clean with and then oxalic acid to neutralize the tannin bleed from the red oak. From there others would use sodium hypochlorite on the cleaning end and even use JUST that at too strong of a dilution because the erroneously believe it is all mold and mildew. Then sodium metasilicate was added to some composite cleaners. Regardless, the proper method older composites is a two step process. Clean the mold and mildew, neutralize the tannin bleed from the wood content. Next, in regards to voiding a warranty of any kind with older Trex this is also wrong information. Planks were made in a vat and when the planks were made for use the wood fibers were more prevelant near the surfaces. This IS THE ONLY REASON they recommended no pressure washing because the pressure removed the light shell and further exposed the wood fibers therefore creating more black spots. These manufacturers came up with a two-step process to address the issues, aided by yours truly, and folks are still trying to wash with one step to less than favorable results. Moving on, these products do stain easily and look a mess after time BUT, they are stainable and the new generations are not. A light stain will make it look better and slightly extend the life of the older generations of product. I recommend that you differentiate between older and newer generations of product before researching recommendations where you could apply newer recommendations to older product and causing more damage.
9 Likes
my self I won’t do a composite deck, its not wood and will not clean up good…
If it’s less than 10 years old, easy. Hit with roof mix and rinse with low to medium pressure. They clean up great.
4 Likes
Almost every house I do has composite decks. I do a dozen 1st gen Trex every year and never had this drastic of a color change. The owners won’t be down till the weekend to see it. I’m going to take a look tomorrow when it’s fully dry. I might hit it with oxalic if it still has tanin stains but that won’t make it grey again… lol.
me personally, I’d try a roof mix on part of it, maybe the steps and see what happens. Can’t look much worse than it does now. Then you’ll know.
I brushed roof mix on a couple of steps. No change. The dry spots looked pretty good just yellow and I believe the deck should be grey. When it gets wet with water is looks spotty.
spray it on liberally and let it dwell about 15min.
1 Like
I’ll try it.
1 Like
I wonder if pygment came off easily before the first wash. Technically, repairing UV damage/oxydation isnt your specialty right? Cleaning is. But @Racer is prolly right, roof mix and dwell time.
I had spotting on this one but not as bad. Applied roof mix, dwell, medium pressure. Evened out.
1 Like
