Efflorescence is ugly, damaging, and extremely hard to remove. And once you think its all gone, it comes right back.
What is Efflorescence?
Efflorescence is salt. The majority of all brick, concrete, and even stucco will have some sort of crystalline (salt) deposit in it. When this material gets wet as a porous material, the salt will evaporate to the surface. This salt residue will ultimately build up and harden, becoming ugly and hard to remove.
There are a few ways to remove it. The easiest way is to use acid and pressure washing it. Using the wrong type of acid will harm the surface. Too much pressure will either damage your surface or just push more water into the material. This will cause it to come back ten-fold.
Apply the proper acid and let dwell. Sometimes it helps to add a surfactant to keep the liquids from drying so fast. Let dwell per instructions on the bottle then pressure wash off. Repeat as needed. Also, make sure you are wearing proper safety protection! Steamworks is known as most effective as a efflorescence cleaner and efflorescence remover.