Hardy Board

Art Oliveri

Roundtable Host 2009
I went to a trade show today. The Sales Rep was there from Hardy Board. So I asked him how do you clean it. He said soap and water. I said no S/H . He said never, it fades the Hardy Board color. So I said what if it has Mold on it. Then he proseeds to tell me that the Mold isn't on the Hardy Board, its on the dust that collects on the Hardy Board surface.
I'm shore many of you guys here washed Hardy Board. How do you wash it and is the mold on the Hardy Board or on the dust.
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Trae R

New member
There is hardi plank everywhere here. I have cleaned deep reds and dark blues with my normal mix and I have never seen a problem. The biggest problem here is they oxidize really badly and the rich colors really fade from the sun.
Regular house wash mix here. Sh and soap. I normally spend just a little extra time rinsing on them though. Never had any issues. They actually clean up very easy.
In my opinion its always to be safe than sorry...its a good practice to prewet .....yeah you might get by not doing so...but if u wash long enough ....it might fade some shades....at least in your customers eyes. I am sure lots of variables come into play.....cheap paint, bad prep work, chems to strong, chems dried on or maybe a customer that is out for a free ride.
In my opinion ...major cause is chems to strong....got over spray on hardy and missed it on pre wet.....and has happened when I have treated gutters without pre wetting.....once that happens....you can't take it out..only try to blead it in to where its not noticeable.....if I notice paint on hardyhas a good gloss.....you can bet I will prewet and cut back on my mix.
Everyone has there on method and reasons......this is mine!!!


Most of the homes I wash, including my own have hardy board on them. They do fade, but that is usually the paint that fades. Cheap paint doesn't stay on it. The contractors paint that was on my home when it was built 11 years ago faded out in 3 yrs. The new paint is 8 years old and I wash it every year. (lots of sh) Still looks good.