Gazebo Cedar Shake Roof & Floor

So I’ve searched and read and watched about everything I can find on cleaning cedar wood/shakes and I’ve found nothing that really says here’s what I use, how I mix it and how I use it.

That said I have a customer that I wash their house last 2 years and she tells EVERYONE about me and gets me tons of work. Anyways she calls me today and asks if I can do her Gazebo. Medium size. 12ft round I’d say. It has cedar shake shingles and cedar floor. She wants it back to “original cedar look”.
Its in good shape other then the roof has moderate algae coverage and light moss and lichen. Floor is just dirty and light algae in spots.

I was going to do
3-4% SH dwell, rinse
Sodium Percarbonate dwell, rinse
Oxalic Acid dwell, rinse, rinse, rinse

Should this not clean it well?
7oz percarb to gallon of water?
3.5oz Oxalic to gallon of water?

Are these mix ratios correct?

Ill be applying with hand sprayer.
Rinsing with light pressure.

Any guidance or info would be greatly appreciated. I’m doing this for her at No Charge just as a Thank you for her business and the business she gets me. I just want to do a nice job for her learn something new in the process.

(She really stressed she wants the original color to be restored)

NOOOOOOOOOOOO!!! 3% SH will destroy cedar. It’ll look like a bad shag carpet from the 70’s.

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You’re right that there isn’t much info on here regarding cedar decks. Cedar is weird stuff. It is very easy to make it all furry with excessive chems or pressure.

Check out this little bench I was playing with. Huge variations in color depending on your process. The right side is before. Upper left is no chems and 640 PSI. Left middle is Sherwin Williams Revive (oxalic). Left bottom is SH. None of them looks bad to me. But you should know which one you are going for and set expectations. If it’s your first one, maybe just do it with no chems. Do a demo if you can.

When you wash houses, the pressure isn’t really critical. The chems do the work and you just have to get some water up there any way you can to rinse it off. If you’re doing cedar, you have to get the right tip. 640 PSI with a 25 degree tip works pretty good for me.


You don’t need the per carb and sh - One or the other. If they’re bad may need the sodium hydroxide. And @instock right, you don’ t need that strong of SH generally on any wood.

If I skip Sh all together, Will the percarb clean the algae/lichen off? Once I get it clean I use Ox to brighten it up?
I’ve watched some videos and the ox is pretty amazing. The thing I’m worried about is she wants original color and I don’t exactly know what “original” color is.
In afraid to lighten it too much.

Don’t worry about. Shakes are pretty light colored when new. You still haven’t posted a picture, so trying to help you blind. Per Carb probably won’t be enough if shingles pretty bad. Usually need to use some pressure with pc which you won’t be able to do probably.

So sodium hydroxide? I can get some coming.
Yea I should of took picture. Thanks for help you can tho. Appreciated. So percarb and ox acid both pretty much mix 8oz per gallon. Is sodium hydroxide same amount. Just want to get it all nailed down then I got it.
If I do it and I prob will I’m just gonna work slow at it and learn from it. Not gonna go burning it up. If anything Ill be light on chems and rinsing too early. I’m a worry wart sometimes😬

Without a pic I’m just guessing.

I understand.
I’m leaning towards passing on it. She just asked of I can apply oil to it once dry. I hate painting! Was gonna do this for free but now turning towards a nightmare. Once she said oil it, free was out the window. So I tried to price myself out of cleaning it at $500. Nope she agreed. Now wants price to oil it! Crap!
Cleaning it, I’d work at it til I got it. But…
I HATE painting!:tired_face:

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Oiling will be the easiest part of the job. Just spray it on with your pump sprayer.

I see😏.

Might just try that. Suppose to hear back today.

Hopefully this before pic uploads correctly but I have the same question as anon61323032 in regards to cleaning a cedar shake roof. What would be the correct method (and Chems) to tackle a project like this without damaging the roof?

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