Straight bleach will degrade limestone quickly and the salt can have a reaction that will turn certain areas that color. To my knowledge their is no way to reverse it. You can try OX but it may make it worse. Might want to call a local natural stone company and see what the best route is.
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Can also be a combo of where the black algae has eroded the surface of the limestone and reveled the coloring beyond the surface… Just saying I may go that route with the customer if that’s the worst of the damage.
Considering the house started like this…
I’m glad I didn’t make it completely orange.
My house wash did nothing to lighten it. Had to hand spray bleach on it.
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Get yourself an X Jet if you don’t want to go the 12v way yet. If your a DS fan only break out the Xjet on jobs like this. Looks great though! Glad things are working out for you
I’m going the 12 volt path. Few more jobs.
Are you sure it’s not well water stains that were just hidden under the black algae?
Sheesh. Wish you guys would ask questions before you did stuff.
First you need to pre-wet. Can clean with bleach with some sodium hydroxide. Need a strong alkaline mix, would have mixed something like EBC with it for surfactant.
Second rinse thoroughly with warm water between 150-180 deg. You want medium pressure , no more than 1000psi.
While it’s still wet need to apply neutralizer to keep the orange stains from coming out. Combination of acetic and citric acid. You could probably go 1/2 oxalic and 1/2 citric. Let dwell just a few min and rinse thoroughly again with medium pressure.
So, to try to fix, I’d re-wet completely and then try the acid mix.
Prosoco makes some good stuff for Limestone or as someone mentioned could use One Restore in the future. Could try some on the orange part, but would try the acid first.
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Heat & pressure is the way as little of each as possible
Very true sir. I didn’t think about an adverse reaction with the limestone. I have many miles, and lessons, to go.
What a PITA to wash…best thing to do is pass on that crap or get paid a pile of money.
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There’s good money in cleaning them. Especially older ones or historic. Really not much difference in prepping a dirty wood fence for staining.
Did you read what you posted? .That was a 3 or 4 part process…including warm water…on something a lot larger than a fence.
Other than using warm water exactly like you restore a fence or deck from a process standpoint. Actually six steps, LOL. You pre-wet, apply solution to clean it, rinse it, neutralize it, rinse it, collect the check
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Better be a big check…
Rick, why are you using warm water to clean fences etc?
I don’t, read the answer again
I am going to call Prosoco. They offer a ton of products. Seems like this is an area I need to improve on.
Racer are you suggesting sodium hydroxide to clean? And then an acid, like citric or vinegar or oxalic to neutralize?
I don’t have hot water but could rent it if necessary.
Yes, pre-wet, SHydrox or SHypo, rinse, Ox or Citric, rinse, walk away with money.
Fine, now I can’t read on top of everything else… I should probably not look at this stuff at 11:30 at night too.
