Limestone Cleaning - Heavy Buildup

Hello all,

We cleaned this limestone chimney today. Soft washed it with about 8 coats of 50/50 SH, even washed some spots with straight SH. It was soaking for about 75 minutes in total. I’m pretty happy with it overall, but the blackest spots from the before picture can still be seen as greenish spots in the after picture.

Is there any way to clean the rest of the discoloration, or is some of it permanent at this point?

Thanks for your help!

Don’t be afraid of a bit of pressure, we’re all men here for the most part.


How much do you find that pressure helps?

I’ve tried up to a 25 degree tip on limestone, but it hasn’t provided much benefit.

I’ve also read that pressure can push the contaminates further into the stone?

It helps a lot, limestone is very porous. The reality is you can’t softwash everything sometimes you need a bit of pressure. Think wood, same principle. You wouldn’t need to wand the whole chimney give the darkest spots a go and see how you go, if you can get it 30% better it will stand out a whole lot less.

As far as pushing contaminates further into the stone I think that’s some faulty publishing in my opinion.

Thanks for your help! I’ll add some pressure to the process.

That looks fantastic, dude! Let it ride and get paid! It is what it is.

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