I finally figured out how to properly remove salt from brick, after several failed attempts. I will give you the short answer right off the bat, TLDR:
Salt is Alkaline. To neutralize an Alkaline you need an Acid. Water or pressure washing is not enough once the salt penetrates the porous surface of brick. Vinegar is acidic, but not strong enough. I used ZEP Calcium Lime Rust Remover.
Who cares what the name is, it is a mix of acids. I am no chemist, but this worked. I am sure the same principle applies with many other products. Sprayed the acid on the affected areas, let it soak, gave it a light scrub and rinsed with a garden hose. No pressure washing at all.
I waited until the next day to make sure that the brick was dry and all the salt was completely gone! (Ok, there was one tiny spot.) But, I have finally found the solution (without using the search function, he he he) to remediation of salt laden brick and concrete.
You made it through that? Now I get to be verbose…
I landed the contract for a plaza and a commercial building to pressure wash the concrete and lower brick with the purpose of winter salt removal, which is extremely damaging to concrete, brick and mortar.
As a PW noob, I assumed that the salt would just come off with my awesome 4gpm 4,000psi amazing new pressure washer. FYI, I live in Canada, and we need to salt all walkways to survive the ice, but, the salt ends up impregnating the lower brick in particular. Have a look see:
This will destroy the brick if not removed, I don’t have a pic of the results of salt damage, but if untreated it looks like the front of the brick has been knocked off once the salt does its damage.
I pressure washed that Plaza and Commercial building, and everything looked great! I was so proud that I had fixed the problem, and had another successful project under my belt. Here is what it looked like when I was done:
I thought I was AWESOME! I used ‘12% SH with an ammonia free surfactant’ with my new upgraded pressure washer.
I had made it. I was worthy of the PWRA. I had the chems, and the hardware, and I had ROCKED those jobs!
However, the next day:
In the words of the ever eloquent Donald: “Wrong.”
When wet, the brick showed ZERO signs of salt, it looked great. But, the next day when it dried, the salt came out in full force. It looked like I had done nothing at all.
So, I trolled this forum some more and gained some knowledge. Here is a cute fact: If you want to get rid of Salt, don’t use SH. BECAUSE THEY ARE BOTH SALT, THEY ARE BOTH ALKALINE YOU IDIOT!!!
I finally switched to acid because it counters alkaline, and here is a shot of the acid working on the left and the salt on the right:
It worked! I took this picture a day later, so it was dry for sure. And, there is a little salt spot, but I know now that I can get it all off.