Hardi board and Sherwin Williams woes

Washed this customers house before I ever knew sherwin Williams paint could cause problems. I was also using 8.25% the first time around Just like @Donut just mentioned in his other post.

This time around though, I asked. Sure enough at Sherwin Williams. I’ve made no secret that I like to go and strong as far as chemicals go on my jobs to reduce time. But this time around I was a little bit afraid.

I decided to take a risk to see if I could mitigate some problems for you guys in the future, but I was prepared to have the house repainted. The front of the house is the only one with the hardy board. So I figured I change my approach.

I soaked the front of the house with fresh water first and did it in 2 sections. Soaped it with my 1% mix.

Turned out great. I called the customer this morning to make sure they were still pleased and missed her. She called back. Anyway I just stopped by the house and no problem whatsoever.

So maybe that’s the golden ticket. Wet the house first like you would a painted Door.

Sorry for all the capital letters, miss spellings, and grammatical error’s. Talk to text would love nothing more than to make me look like a huge idiot.



Our area is growing fast… they cant get houses quick enough, and this is the only siding they are using. All green, blues, greys, browns, etc.

Its only a matter of time before these ppl start needed house washes.

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Can’t really trawl whay color that is on my phone but the SW colors to avoid are blue, red, green, and brown. Prewetting with help on those. Amd it’s not every time. But the percentages are high enough to avoid them


Would a call to contractor be the only way to find out what paints were used?

Unlike Mr. Squidward, im not prepared to pay for a repainting.

This a bluish grey. Definitely has blue in the mix. But it’s not a deep blue or any of the other problem colors you mentioned…

So maybe my testing was in vain.

when I doubt, walk away. I personally won’t spend my time calling paint contractors

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You could wash 9 with zero problems and get one that messes up. I’ll still pass

Out here most of the houses are Hardi-board with some vinyl thrown in.

For those guys who need work and can’t walk away do a test with your mix in a inconspicuous area first.


I have a lot of Hardi Board in my area. Not a lot of blues, greens or reds, but a lot of tans and browns.

We all know you receive forum printouts in the mails. The printer was probably running out of colour.

Let’s not pretend you’re able to use a phone now old man, I cant handle a joke that big so early in the morning.


Down here we run 2% downstream and EBC. We can rinse at rong range at 2000 psi 25 lpm. We don’t have problems with paint?