Whats the best way to clean this building?

Going to be taking on another commercial job in about 2 weeks but im not sure what type of material it is (its almost like a styrofoam that has been coated in some type of cement material). Looks like a hot house mix DS on that portion should do the trick and for the brick straight house mix i would assume. However, its a rehbilitation center for senior citizens so im skeptical on using that type of stuff in this area. What do you guys think? I have attached some pictures.

3% on all of it. 4-5% would be more efficient in a single pass, but old people might be more affected by the smell. A few passes with 3% should get it done though

In other words, your DS injector isn’t going to cut it, @theotherguy.

xjet might do it if you start with hot enough bleach. Direct application with a 12v or similar setup would be the most fool proof method.

The surface is either Dryvit or EIFS (faux stucco). I’ve never washed the stuff, myself. But I’m a sponge for information, lol.


I xjet those rather than 12v. Ive done several stucco and Dryvit with x jet. Its about all I use it for


so just xjet the whole building with a house 50/50?

Id start at 3% and see if it gets it done and increase strength if not satisfactory

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ive got to be honest im not sure exact what you mean by 3%. also, ive had an issue with using house wash on brick, it just never stops producing bubbles due to it soaking in to the poors. should we use a different cut for the brick with no surfacant?

Man, you need to do some reading. You start with 12.5%. Lets call it 12 for the sake of easy math. How many times do you need to cut down 12% to get to 3%? 50/50 gives you 6%. Too strong. More than needed and a waste in most cases. It will kill grass and in this case is likely to irritate some old people lungs. Too much bubbles? Too much soap. Cut back on it. Also a waste at that concentration.

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This 3 and 4% business started a few years ago. It is technically correct but extremely confusing. the industry standard bleach we use is 12.5. Pour 5 gallons of bleach and 5 gallons of water in a tank and you have a 50/50 mix. It is that simple. Ignore all the complicated ratios. I typically use pressure on brick and don’t soap it.

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That sounds rough. Price in a bandit and 55 gallon drum. You’ll thank yourself.

3% or a 1/4th of 12.5% is simply a 3/4 of a barrel and 1/4 12.5% bleach. Or about 13 gallons into a 55 gallon drum. No need to be super exact.

Updated: We start this job at the end of the week, the plan of attack is to start out with a batch mix and down stream through a 20% injector on the light stuff. Will be getting ordering an xjet tomorrow for arrival on wednesday and running the same batch mix with the xjet and no proportioner (i believe thats 3:1) for the heavier spots. Wish us luck! Not 100% sure how long this ones been dirty so lets pray for minimal staining on the siding!

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Batch mix of?

I’d be going neat if you’re DS’ing.

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“going neat”? im not familiar with this Australian lingo :joy:

Ha ha :blush: …well a batch mix implies you’re diluting the SH with water.

Going “neat” as in using the SH neat (no water) to downstream :+1:t2:

Those ratios come from the same guys who hold the monthly corporate meetings for their company and employees…lol

I’ve read some post that it’s closer to 1-1.

nooo i will be starting with a 50/50 through a 20% draw. Should roughly be 1.2% if my mathematician skills are correct

I think you’ll need stronger for that from experience.

Straight SH @12.5% will be 2.5% (maximum draw) with a 20% injector.

1.25% might move some, but 2.5% will get more, if not all.

Just my 2c :call_me_hand:t2:

the plan is to give it a shot at 1.25% on the light stuff. Heavy stuff will be xjetted with 50/50 and go up as needed

From my limited experience DS will barely touch any of that unless it’s painted.