I’ve read a ton of threads about cleaning limestone, consensus seems to be a really strong hit of SH, dwell and rinse thoroughly.
Now this house is quite old and I’m just making sure to do a good job. I’ve read it could turn it an orange hue and trying to avoid that, someone mentioned Prosoco or One Restore, would that be diluted quite a bit?
Not all limestone will turn orange, it depends on the iron content in the stone. I don’t really see much existing orange peaking out of that stone, so you may not have any issues.
I’ve mostly read to neutralize with oxalic acid if it’s turning orange.
Wait for others on this one…
You’re dead on @sixsolve . Nuke it @dcbrock . On some of those bad ones, will probably take at least a couple of coats, wait 5-10min in between. I usually just use a standard roof mix, about 3.5-4%.
Nice, she will be thrilled. This will be my first limestone job so a little excited about it.
Keep applying until the brown is gone… it may turn an orange hue, so don’t freak! That’s the detergent working…give it some time & rinse it out good…get as much off the stone surface, then apply again, & repeat…ect.
We use a 6% mix, best results are in high outside air temperatures.
I’m a little leery of the color change, a local guy washed a cemetery vault building and turned the whole thing orange so trying to avoid that result.
Just have acid on hand, I usually neutralize after on limestone myself, but definitely rinse a lot. You will be fine, get some after pics.
Just do you a test spot and start someplace relatively inconspicuous. Just have some ox on hand if you need, but doubt you will.
Thanks guys, I’ll do a before and after here in a couple weeks when I get a chance to do it.
