Cleaning Limestone

[Tuskey 14]

First of all, I'd like to say hello to everyone and thank anyone for any help they can provide me.

My name is Amanda. I recently started up a pressure washing business after going to get certified to clean kitchen exhausts. I have a 3300 PSI 250 degree 5.2 GPM unit on a 16' enclosed trailer with a 225 gal water tank, hoses,... blah blah blah... not really important I guess... I AM also insured with 3 million gross insurance (I know that's a biggie).

Anyways... to say the least I really am VERY new to this whole pressure washing thing and aside from doing the kitchen exhaust cleaning (which I feel confident in after the course/certification) I am not very knowledgable (yet) on the other aspects of pressure washing, although I truly want to learn the correct ways to do things and of course in an efficient manner. I have done a lot of searching on the net for tips etc, but I have really had a hard time finding any answers for how to correctly clean limestone.

I also own a window cleaning company which I've had for almost 5 years now and a recurring residential customer of mine just recently asked me about pressure washing her 1 story house that has some limestone walls/walkway/patio (the majority of the house is brick, but she's not concerned with getting that cleaned right now).

From what I've gathered through searching I should use low pressure for sure, and I read a little about use SafeRestore as a possible chemical, but other than that I really don't know much else. :( Like I said earlier, I definitely wanna learn the correct way to do things so I don't damage her property. Could anyone find it in their heart to help me out with some information on this please? I know I'm a newbie, and I probably have a lot of "dumb" questions, because I just don't know yet, but everyone has to start somewhere. So please be nice :) and I'd like any info that y'all are willing to give. Thanks for your time.

[Richard 17]

Hi Amanda

Welcome to TGS. Just a friendly reminder, you need to add your signature, before most people will help you.

There is quite a few people on here that have done Limestone cleaning and restoration. You can also check www.prosoco.com and www.diedrichtechnologies.com

[big mike 14]

www.eacochem.com Lots of info on their site, or call them for directions.

[James 624]

On walk ways and patio's do a test spot with hot water and low pressure First. Then move to a bleach and soap solution. I take care of a few big ones and this works. This also will turn into a recurring thing.

[Tuskey 14]

Sorry, I wasn't paying attention about the signature until after I already posted, so here's a sig check...

Also, thank you for the eacochem link. That's actually where I came up with the SafeRestore info for a possible chemical... However, that website is messed up and a lot of the links are broken once you click on them, so it's kind of frustrating.

Edited November 6, 2009 by Tuskey

[Richard 17]

Call Mike at EaCo Chem 1 800 313 8505. He's a great help.

[James 624]

There is no need to go nuts with acid on walk ways. It's good to have on hand.

[Cat Powerwashing Inc. 17]

When I clean limestone, I first blast with a turbo nozzle, once all the heavy krud is off, I then apply straight chlorine onto the surface. It comes out like brand new!

[Henry Bockman 14]

When I clean limestone, I first blast with a turbo nozzle, once all the heavy krud is off, I then apply straight chlorine onto the surface. It comes out like brand new!

What the hell kind of advice is this??? Limestone is a very soft surface to clean.

DO NOT use a turbo on limestone. If you do, it will cut it up and abrade the surface of the stone.

DO NOT use strait bleach on it either, it can turn it orange.

My suggestion would be to contact Prosoco, they have the best customeer support around, Eachochem has dissapointed me too many times in the past. I would suggest using Limestone Restorer, if you need soap, sometimes very hot water at 600 PSI will clean it up just fine.

If you have any questions feel free to give me a call, we clean a lot of limestone, brick, marble and other substrates and I'd be happy to talk you through it.

Edited November 9, 2009 by Henry Bockman

[Lightning Gene 66]

Welcome to TGS

[sweetwaterfish 15]

I have found that pressure and limestone are not always compatible. We recently had a pool waterfall with limestone which had literally turned black with mildew and algae. Our weapon of choice was a pump-up sprayer and a solution of 30% sodium hypochlorite and 70% water. Let it dwell 10 minutes and then rinse with low pressure(garden hose). The orange is usually the dead algae and can be rinsed off. The rinsing may take a little while since the limestone is so porous.

Edited November 10, 2009 by sweetwaterfish
addition

[Cat Powerwashing Inc. 17]

Henry,

In response to your comment. I have never damaged one stair tread yet doing it that way. It comes out like it was just installed! If it was ohio stone (which you cant get around here anymore) I would say no way! It is very soft and yes it would carve it up like a thanks giving turkey. Why spend money on a specialty cleaner when you can use hot water and 12.5% SH? Its only mold and mildew stains! Of course we always test before we blast!