Retaining wall help

Hello all. I have the opportunity to clean a retaining wall (split face block) and need some help pricing it. Do you price it out by linear foot like you would a vinyl fence or calculate the square footage and go with my regular rate that I charge for concrete? Or just guesstimate how long it will take and price accordingly? Any thoughts or input would be appreciated.

It is 350 feet long and averages about 4feet tall. I will go by tomorrow and do a couple test spots to see how easy/hard it will clean up. I am unsure how long it will take since I haven’t done any retaining walls, but most of the dirt looks to be mold/mildew/algae. There is some calcite which would have to be treated separately and priced accordingly but my main question is how to price it out. Any help is appreciated. Thanks.

I would be at 60-75¢ a square foot. I think pre treating with 3-4% would help but that’s the job of a turbo nozzle. I’ve done one of these that was 30 foot long at a house and was only 3 foot high. I had to turbo the whole thing. And with all of the crooks and crannies your gonna be soaked from head to toe by the end of it. I know I was…


Make sure the city is ok with that. Some places you cannot wash a retaining wall without trouble.

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Ok. That’s pretty much what I was thinking, that it wasn’t going to be a quick and easy job and needs to be priced accordingly. Thanks for the help.

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@Jsib Not sure about your pricing, but wear glasses!

To get into all the places properly gets you covered in…SH (not sodium hypochlorite!)

They come up good though:


A $12.00 Tyvek painter’s suit will be your friend. They are not completely water proof but pretty good for this type of thing.


Yea I just bought a full face mask after getting soaked on another job last week. Looks like the wall turned out great for you. I have some Sodium Hydroxide I can use. That works good on brick/block?

Yea I’ve been needing to get one anyway. I’ve got a few jobs that you’re naturally going to get wet. No way to avoid it.

Most jobs, unless in corners or tight spaces - I just wear old sunglasses.

These walls literally flick grains of sand at you from all angles though, so better safe that sorry.

I pretreat almost everything. Others here only post treat. Either way, I’d test a spot with no chemicals first, you may find it works and you don’t have to spray anything saving time and money.

I usually downstream a strong house mix afterwards to help rinse and leave a residual for a nice even finish.

Oh, if you have a small surface cleaner, run it across the top, saves you heaps of time!


I personally would price this one by the hour/day. The wall height is not even all the way down, so lnft, or sqft would be off as the wall height gets shorter. But really it shouldn’t matter, my sqft/lnft would match my hourly.

For this i would use my roof pump and spray a 4% pre treat, than come back with some pressure. Than depending on how it looks would post treat it.

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Thanks. I think a strong mix will help a lot. Plus I have an 8gpm hot unit if hot water will help. I’ll go by tomorrow and do some test spots. That will tell me how long I think it will take.

No sodium hydroxide. Turbo nozzle and three hours of your time. Add an hour to rinse pavement if they don’t have a street sweeper that regularly maintains the parking lot

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Walk down along it spraying 4% mix, wait 5 min , turn around walk back the other way spraying same mix but hitting it again at a different angle, then use your adjustable wand to rinse. In fact last one I did, just used my downsized m5ds nozzle to rinse with. IBS right on 3 hours though. He’s younger than I so he likes to work harder than me though ie turbo nozzle, lol.

Look online, can get the tyvek suits $4.95 though to be honest that one not that bad. Good suggestion made hit with strong hw mix when you leave.


Done right, that should make for some great b&a pictures. Get it!

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Awesome. Thanks

For sure

What do you mean here. Smaller one, more pressure?

yes, have one for my 4gpm too(think 3-7pgm size). When used with the 8 gives you about 50% more pressure. Great for some applications.

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Great info. Thank you @Racer