A Little Advice Might Be Nice

“No Bleach!” The customer demands. This job is actually for a painter who sends me lots of business, which is why I cannot heed @Innocentbystander 's warning to run away from this job. (I heard your voice in my head as I drove up to this beachhouse)

My job is to prepare the shingles for staining, but also to clean the soffit. Advanced colonies of algae grow in a few areas, and some of this soffit is 35+ feet up.Most of the soffit is just covered with salt and sand, but there’s an area 40’ up where the dryer vent has a lot of black around it. What cleaner will be most effective in this assault that isn’t SH. ALSO, decks and windows may be added on if we’re effective with the siding and soffit: the decks are either IPAY or teak, and I’m thinking Sodium Percarbonate at 25% solution pretreat, dwell for 5 minutes and pressure wash.

What does my braintrust think? This is definitely NOT the standard job.

Try some “I Can’t Believe It’s Not Bleach!”


Sodium Hydroxide


I would try citrus house wash and hot water

Sodium Hydroxide for?

I don’t need to tell you @MrSparkleVA but for the new guys, do a test spot first. Ipe is usually Mahogany and is pretty hard. It reacts quickly to SH. I’ve never used sodium percarbonate on it.

It’s a deck stripper
It’s what I would use on the shakes

Sodium pre carbonate??

Another thought would be to ask if you could do a small section out of sight using SH so you can show him it’s the best way to go–like maybe a 5’ x 5’ area.

If he’s open to it, then once you’re done and you show it to him, you say, “This is the best way to do it and it will produce the best results.” And let the results speak for themselves.

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My second thought, which will likely be shot down (and maybe for good cause), is to pressure wash the whole thing with no chemicals.

I don’t know anything about cleaning roofs. And I’m still learning about cleaning houses and concrete.

But one thing I did for many years was clean and stain enormous condominium complexes that were all cedar siding. Pressure washer and ladders.

Maybe there’s a better way to go today, but if you’re hand-cuffed due to chemicals, it’s an option.

You definitely don’t want to blast cedar shingles with pressure.


Nothing wrong with using pressure on wood as long as you don’t go more than around 800-1200 psi. You have to use some pressure to blast off the dead layer of wood. You really should use some chems though. You might clean the green and black off with pressure but not sure that it will kill all the algae and mildew spores. Chem selection can be different depending on type of wood or if it’s going to be stained afterwards. If it’s going to be stained you should also apply a wood brightener/neutralizer. I’ve never dealt with Teak but sodium percarbonate is really mild so I’m sure it would be fine. When I’m doing a deck job that is going to be stained I usually use sodium percarbonate because there’s less of a chance of the wood furring compared to using sh which means less sanding. Although, it usually takes a little scrubbing on the deck boards to get the best results.


I’ve always heard not to use hot water on wood. One reason being is it causes the wood to swell trapping in the chems you’re using. Not sure how true it is but makes sense.

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I see where you are coming from but I dont think it swells that fast. I use hot water on wood all the time never had any problems

Check out [Sullivanroofcleaning . com]

For what?

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He used to sell a training course on cleaning cedar shake I believe. I think he uses all the softwash systems chems

Sorry, Just trying to advise him of someone who has done a lot of this type of work.

Are you referring to Sodium Hydroxide, IBS? The painter is putting a very dark stain on the shakes, so all I need do is wash off the sand and salt with a few areas of algae. If I used NaOH on the siding, wouldn’t I need to neutralize the pH before the stain is applied? I REALLY don’t want spray either that 35-40’ up with beach wind blowing constantly. I’m all for a nice easy cleaner, and I think I WILL employ heat for this one.

You still may need a citrus cleaner. Just remember heat doesn’t mean all the way up around 100 should work just fine

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