# Washing Composite Decks



## Rick the painter (Mar 30, 2009)

I was told only to use a prouduct called Corte - Clean on composites. Im wondering if the cleaner doesnt contain bleach,will it kill black mold? The porch that were pricing is only two years old,and in the shade so we dont want to alter the appearance at all.


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## PressurePros (May 6, 2007)

Mix bleach half with water, add a little Tide or TSP, brush on from 5 gallon bucket, rinse with garden hose, collect check.


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## NCPaint1 (Aug 6, 2009)

PressurePros said:


> Mix bleach half with water, add a little Tide or TSP, brush on from 5 gallon bucket, rinse with garden hose, collect check.


Yup. You can spray it on too. I tried spraying cleaner on with an airless....it works pretty well of you reverse the tip. Basically just spray it on with the tip in backwards, puts it on real fast.


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## ReNt A PaInTeR (Dec 28, 2008)

I thought that bleach would damage the packings on the pump


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## NCPaint1 (Aug 6, 2009)

ReNt A PaInTeR said:


> I thought that bleach would damage the packings on the pump


No idea, so far so good :thumbup: I wouldnt spray any caustic stripper though. That might strip any residual paint in the pump/line and cause issues, just like running lacquer through a pump primarily used for latex. The stripper I used was Safe Strip, and no problems, and have also run TSP/Bleach/water mix with no problems. I liked it because it put it on hella fast. Using a pump sprayer is hard to keep everything wet when its 90 and in direct sun.


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## Retired From Paint (Jun 12, 2011)

Rick,

Corte does not contain bleach that will lighten the composite.
Corte is recommended by most composite manufactures.
Do not void the warranty by pressure washing above 1500 p.s.i.
Always test the product first before making any asumptions on the 
time and labor involved.

Best reguards


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## PressurePros (May 6, 2007)

Bleach is fine in the right dilution. Too much and you can dramatically fade the composite's color. Too little and the mold will not be killed deep down in the wood fibers (the organic part) of the deck. The secret is to brush. It makes a difference. If you are going to apply via pump, get a cheap 12 volt. Paint sprayers flow a third of a gallon and they are way too expensive to risk. For $120 and another $85 for braided 3/8 line and low pressure gun, you can have a 5 gpm pump that will let you apply deck stripper or house wash mix up to 30' high.


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## Retired From Paint (Jun 12, 2011)

Good point-- No bleach how do you kill the mold & mildew?
Corte does not address the subject. They would more than likley tell you to clean more often.


Best Reguards


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## Rick the painter (Mar 30, 2009)

Thanks PP & Retired....

The Corte-Clean instructions are a bit confusing...They tell you to cover glass,chairs,etc. What the hell is etc? Theyre not specific.What about the friggin plastic hand rails that surround most composite decks? They also say that bleach doesnt REMOVE mold,it just kills it and it returns later.I heard similar stories from an old timer years ago.Too much bleach will fade it,and so will too much Corte- Clean.Just a buch of baloney,i guess ill use it because the customer insisted.....


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## PressurePros (May 6, 2007)

Rick the painter said:


> Thanks PP & Retired....
> 
> The Corte-Clean instructions are a bit confusing...They tell you to cover glass,chairs,etc. What the hell is etc? Theyre not specific.What about the friggin plastic hand rails that surround most composite decks? They also say that bleach doesnt REMOVE mold,it just kills it and it returns later.I heard similar stories from an old timer years ago.Too much bleach will fade it,and so will too much Corte- Clean.Just a buch of baloney,i guess ill use it because the customer insisted.....


I have heard that silly anti-bleach mantra from other vendors and contractors. I wish someone could tell me how it is physically possible to kill mold yet have it remain and regrow. As far as my understanding of nature goes, dead is dead unless we are talking about a zombie movie. Bleach is an oxidizer and so is sodium percarbonate (the ingredient in Corte Clean). The difference is sodium percarb is a slow and expensive oxidizer. You have to apply it several times with very long dwell times to be effective. If there is any chance of mold "growing back" it is using a cleaner containing sodium percarbonate.

A simple science reality check for these companies making bogus claims. Decks are outside. Of course mold will grow back. It doesn't matter what you clean it with. Anything said to the contrary is deceitful marketing.


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## Rick the painter (Mar 30, 2009)

Thanks Ken,Your the man.We used it today and it cleaned the floor well,but.....like you said it was very slow. It also never removed green mold that was present on the outside trim around the deck.Luckily i had a bit of bleach in my garden sprayer left over from yesterdays wash job!


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## Retired From Paint (Jun 12, 2011)

Rick,

I am glad to hear it worked out, hope you made some $$$$

Would you use corte cleaner again ?


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## Rick the painter (Mar 30, 2009)

Retired,
Well,i guess i would have to do a side by side comparison with say bleach only.It did clean some grease stains out pretty well.Ive been washing houses for 23yrs and only have used bleach. I did call Corte-Clean with a question and my call was never returned....what a croc.Thats **** service as far as im concerned..Rick


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