Smooth Stone

any ‘semi’ quicker way to remove the stain at the crown there between the stone and stucco? I’ve hit the stone with 4-5 passes and it’s cleaned up but the smooth stone is VERY stubborn. I’m almost at the point to bust out the extension pole

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What percent mix? Keep going up in % and continue with multiple passes. I think you’re on the right track with agitation in between those passes.

Right around 5%. And by extension pole I meant telescoping wand. Though I’m jk. It is lightening up w hotter mix. Just not as fast as the porous stone

lol…I was thinking you meant pole for some reason. If you pull out the telescoping wand be sure to record a video. You never know what will happen with one of those! Go straight if you need to. Just test the stucco first or make sure you keep it on the stone. It shouldn’t hurt the stucco but you never know.

so I applied one restore To the left end of the extrusion here and the stains did not lift. The stone was moist from previous rinsing. Not completely dry. I’m guessing brush on some straight SH with some surfactant and let sit. Anywho just sharing my journey here. Coming back next week to wrap up the north end. More rain in the forecast so calling it a day. Thanks for input

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I for one think it’s looks pretty dang good man. Nice job @3martineza

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Hmm, so your the one cleaning the old bank off of I-35 and 79!

I know you joke about the pole, but as the stone is super tough compared to the softer lower bits - I’d just do it. Hit it :facepunch:t2:

Throwing more and more mix is one way, but getting it to dwell just there doesn’t seem to work so well (you can see the runs where it’s working/not I mean).

Not that high, throw some mix on it and brush it. Sometimes on those just a light brushing will clean it. If not jump up on a ladder with a squirt bottle of sodium hydroxide in it and a tire wash brush if that’s what it takes. But I’ve had to hit stuff like that 6-7 times with 50% and then pretty good pressure to get off.


We have a lot of that in the Austin area. It is sanded or honed limestone. Can be slightly rough but smooth to completely smooth surface. I usually hit it with 12.5% and keep it wet with mix for 20-30 minutes. It is the only thing I have found that gets it clean. My theory is that since it is sanded or honed, the surface pores are partially closed or smoothed out, so it is harder for the stone to soak in the mix to kill the mold. By keeping it wet with mix for longer periods, it will eventually soak in enough and deep enough to kill the mold. When these stones are used on the ground for landscape boarder, you will never get them 100% clean. No matter how long you keep it wet with SH they just don’t clean like stones on building and walls.