Soot and chimneys

Hey everyone, I’m going to be washing a natural stone chimney typical mortar between the stones. This is for a family member that mentioned he took a power washer straight to the stone in a attempt to get the black soot off. He claimed to have zero luck. Before I go attempt anything, does anyone have any experience cleaning soot off? Sounds like it’s on there heavy. Quick searches only showed to use vinegar/water mix, this recipe looked to be aimed at cleaning soot from the interior fire place surround. Any suggestions would be greatly appreciated. I will post before and after pictures in the future.

I’ve yet to use it but I’ve read on here people having success with EBC for soot.


There’s some info in this thread.

1 Like

So this is the chimney . It’s a sand stone type of texture, very gritting. All the black is the soot. Front of the house has same stone and it is very clean. I tried the following, Water/vinegar mix, SH %12 in all strengths, and muriatic acid. I’m going to say other than some surface grime none of these solutions worked. My turbo nozzle was the only one to remove anything and that was the top layer of the facade. Can’t do it that way. I’m assuming the stone and soot have had some sort of reaction. I tried CLR also now that I remember, foamed a bit that’s about it.

Some of that might not be soot. Apply a 3-4% sh mix with a pump sprayer and see if it reacts. Then rinse really well. Apply a strong caustic degreaser.industrial purple by zep from home depot works pretty good and is cheap if you just have this one job.


You say its a sand stone type of stone. Find out exactly what it is. Theres company’s that make products for specific types of masonry. That would probably be your best move. If the brick is soft be careful hitting it with high pressure.

Hit it with about a 4% mix, let dwell 10min, hit it again, let dwell 10 min and then hit it again, let dwell, Rinse off. Protect any plants below from splash and runoff. Don’t rinse in between. May get away with 2, but will probably take 3, maybe more.


Try oven cleaner