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plainpainter

Trex - host for mildew?

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I did this trex washing last year - typical hand brushing with good strength bleach and detergents. It was really bad - included lichens on the handrails on top of the deep seated mildew.

Anyways - customer calls for a 'maintenance' washing - so this time it's all downstreamed. I couldn't believe how bad the mildew had gotten in a year's time. They thought it still looked pretty good - even I thought so - but when the bleach started going on and I started looking closer in certain corners - it was downright ugly! Some areas needed 5-6 consecutive applications - a few spots were so bad they didn't come out at all!

And this was just a year after I brushed the entire decking and got it spotless! I would have never thought that even on trex - that the mildew would have returned so soon?

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Composites, especially in healthy mold environments, can be a twice a year maintenance. We do the same process every time. You need 3% + hitting the deck and usually brushing, to get it completely clean. How ironic that to keep the deck looking good you have to clean and seal on the same schedule as you do a wooden deck.

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How ironic that to keep the deck looking good you have to clean and seal on the same schedule as you do a wooden deck.

hmmmm.....funny that.....

The 'maintenance' wash pricing is for the downstreamed 'juice' - definitely doesn't do as good a job. But I want the 'maintenance' money each year - so the results are the results

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Trex decks along with any other composite decks are made up of plastic and saw dust. Now when the decking gets wet the wood in the decking absorbs the waters, snow, etc.

Now, we all know what normal outdoor wood does in the weathering process, it turns gray because its a form of mildew.

Well, the same thing is happening here with composites, but its actually leaching out from the inside of the composite structure.This is why you see the black spots on composite decks. The Black spots is the wet wood mildew trying to leach out, but it also has plactic that also involved in the making of composite structure.

So just like Ken says, You have to clean and kill the mildew and now seal the composite to keep the water out from attacking the wood in the composite.

Just always look at a customers composite deck, and under the soffet area of the house you will see nice beautiful composite clean deck. Or look at a area where water does not get on (like under a umbrella base).

This is the same as wood stains on wood decks. The wood stain will look beautiful on areas of the decking that does not see the weathering process and is protected from the Rains, Sun, Snows, Mother Nature, ETC.

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Dear Mr. Daniel Tambasco,

I am a representative of Trex and would like to comment on cleaning mold and mildew. Periodic cleaning of Trex decking will remove dirt and pollen that can feed mold. We do make recommendations of cleaners that are effective in removing mold and I would be happy to provide that information. We do not recommend power washing as it may cause damage to the deck. Please contact me diretly to discuss further.

Pat M

Trex Company

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Pat,

Its been a while, but your company has hired me in the past to perform warranty cleanings for TREX decking. As you stated, pressure washing is a no-no for ALL composite decking. Regular cleaning will keep it looking good, though the dreaded "black spots" keep me busy. Are you still recommending sealing?

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Trex decks along with any other composite decks are made up of plastic and saw dust. Now when the decking gets wet the wood in the decking absorbs the waters, snow, etc.

Now, we all know what normal outdoor wood does in the weathering process, it turns gray because its a form of mildew.

Well, the same thing is happening here with composites, but its actually leaching out from the inside of the composite structure.This is why you see the black spots on composite decks. The Black spots is the wet wood mildew trying to leach out, but it also has plactic that also involved in the making of composite structure.

So just like Ken says, You have to clean and kill the mildew and now seal the composite to keep the water out from attacking the wood in the composite.

Just always look at a customers composite deck, and under the soffet area of the house you will see nice beautiful composite clean deck. Or look at a area where water does not get on (like under a umbrella base).

This is the same as wood stains on wood decks. The wood stain will look beautiful on areas of the decking that does not see the weathering process and is protected from the Rains, Sun, Snows, Mother Nature, ETC.

Tony,

What are you sealing it with?

Beth

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:lgmoneyeyI have a lot of customers with "Maintenance free" and/or " Low maintenance" Trex decks.

I'ts way easier to see mold and mildew on trex decks than on regular color wood ones.

Many mildew problems in a first year . I have bunch of pictures of "new" trex decks with round mildew spots all over them .... we should call it trex disease :)

Just my private opinion only and hundreds of pictures to proove it ...

On many decks which gets enough sun and little or no moisture there is no problem with that ...

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Dear Mr. Daniel Tambasco,

I am a representative of Trex and would like to comment on cleaning mold and mildew. Periodic cleaning of Trex decking will remove dirt and pollen that can feed mold. We do make recommendations of cleaners that are effective in removing mold and I would be happy to provide that information. We do not recommend power washing as it may cause damage to the deck. Please contact me diretly to discuss further.

Pat M

Trex Company

Pat,

Using a bleach/soap/water solution, or a percarbonate based wood cleaner, we do pressure wash the handful of Trex and composite decks that we service.

Low pressure, but pressure wash none the less. Faster, less expensive for the customer, and results are superb.

On a side note, when are you going to train your installers to leave a gap between horizontal deck "boards". We've had to remove, rip, and route an edge, and reinstall on more than a few occasions. One job comes to mind where the Trex actually buckled up. Too many Trex installations have no drainage and pools of water create an ice skating rink in the winter, and a mold and mildew nursery in the summer.

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Dear Mr. Rick Petry,

Our precautions on power washing are listed on our website as well as our specifications. Gapping is very important and is addressed at length. Trex decking must be gapped, both end-to-end and width-to-width. Gapping is necessary to facilitate proper drainage and for the slight thermal expansion and contraction of the Trex decking boards. Another reason for gapping is to account for shrinkage of the wood joist system. Our gapping requirements are listed in our Installation Guide as well as on our website. You are definitely correct that ponding water will breed mold and mildew.

If you have any further questions, please feel free to contact me directly.

Pat M

Trex Company

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So far I'd say 100% of trex composite deckings I come across have no gaps whatsoever.

Pat - please send a thanks to your president for your 'no' or 'low' or however you advertize your product's maintenance schedule. As I make tons of money doing maintenance on them.

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Dear Mr. John Orr:

Trex decking does not need to be sealed for protection. But if you decide to seal the deck, we first recommend that the deck is thoroughly cleaned and dries. We have cleaning suggestions listed on our website.

Trex decking can be sealed using the recommended protectors from the following companies of:

- Problem Solving Corporation

- Sun Frog Protective Products for Exterior Surfaces

- Rhino Hide All Weather Armor

Please contact me if you have any further questions.

Pat M - Trex

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Pat,

I think I speak for many when I say "Thank you" for addressing this issue directly with those of us that work with your product. Our cleaning customers are yours as well, so its to all of our advantage to make and keep them happy.

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