Cedar shake house wash

Hi everyone,
I am pricing a house wash for a new client. They have cedar shake siding in lots of parts stained solid color brown. Stain appears in good condition and they are not loking for a strip and re-stain just cleaning dust dirt and spider webs off.
Question is will standard house wash mix be okay on this?

Ive never done ceder but I beleive you need to neutralize the sh with some sort of acid afterwards. Oxalic or citric.

Pretty sure @racer has experience with this kind of work. Maybe he’ll chime in.

Don’t use sh on the cedar maybe try sodium hydroxide . I believe sh will bleach it

That looks like heavily stained or painted shake Shingle. I don’t have any experience with it while it’s painted or stained but I have done 2 homes that were natural (no stain or paint) and used about 3% sh in it to whiten it up.

Not that this helps you in any way other than letting you know sh will indeed drastically whiten natural unstained shake shingles.

If its just dirt and webs, no microbials, just use elemonator.

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Agreed just lightly wash with NO SH

Yeah they are essentialy painted dark brown… when i first got there i figured it was viynl made to loom like shakes.

Are the gutters and soffit dirty? Hard to tell in pic.

Yeah they have dirt cobwebs and some greening on them. I know i need to use a regular mix there. Just not sure with the shakes being essentially painted if its fine to.do yhe whole thing.

Just use a weak hw mix then if mildew not bad. Just prewet siding well and then rinse soon as you can. Should be fine. Do a little 10’ section in back if possible just to test. If it’s going to run, then it will do it quickly. You’ll see then stain coming off when you rinse. But looks like a solid color stain, so you should be good.

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Newbie here-
I got this job coming up soon. It’s hardie board with a stained cedar shake section just in the front. This will be my first cedar shake cleaning, so I’m thinking a .75 mix in the front with little dwell time and rinse rinse rinse? Im also gonna do a test spot with the .75 just to make sure. Would you veterans go with just soap and water instead?

Are you sure they’re real cedar shakes? Hardie board offers a product like that. From pics, looks pretty standard pattern and a pre-finished product.


Those for sure are not real. I have lots of houses like that around here and normal house wash is just fine on them. I just spray them and rinse right away and rinse a lot because of the color.

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I’d be lying if I told you I was 100% on their authenticity. I was walking the prop with the owner and asked him if that’s what it was and if it was stained, and he said yes. He could be joshin’, but I’m a lil ignorant on this one so I figure I’d treat it as if it were real. Sold & scheduled with enough time for due diligence lol

So by looking at my pics it looks too perfect to be real, right? I’m sure an in person look n feel would be a way, but I youtubed synthetic cedar shakes n saw this.


Just rub your hand over it, you get a splinter probably a real shingle, if not the hardie board type. Plus, absolutely no one would put a solid paint on a real shingle.


Thank you, Sir!