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Efflorescence Removal

Removing Efflorescence

Usually, it is best to simply brush the salt deposits off the surface with a stiff broom. The use of water is not always recommended. The water can dissolve some of the salts and actually drive them back into the masonry. They will subsequently re-appear when this secondary water evaporates. In the most severe cases, dilute solutions of muriatic acid can be used. However, BEWARE of this method. Muriatic acid can cause serious eye and skin burns. The vapors are also very toxic. Muriatic acid, improperly applied to a masonry surface, can 'burn' the brick and cause discoloration.

Sealing Brick

Brick that is still experiencing efflorescence should not be sealed. If you do this, there is a possibility that you can actually damage the surface of the brick.

Efflorescence growing in the mortar of a brick fireplace. Photo Credit: Michael Hannum


The sealer can actually block the movement of salts to the surface of the brick. Now, you may think that is not such a bad idea. Well, here is what can happen.

The salts work their way to the sealer at the surface of the brick and stop. The concentration of the salts increases as the water evaporates. In certain instances, the salts begin to crystallize. This process of crystallization can create enormous pressure on a microscopic level that can actually cause the face of the brick to pop off or spall.



2 Responses to Efflorescence Removal

  1. My basement concrete block foundation walls were painted white with UGL sealer, I'm told. Efflorescence is pushing that sealer paint off and eroding some of the mortar and the block face. The soil of part of one wall was dug out, wall sealed and backfilled, but the efflorescence continues.
    If I just brush it off (inside) as recommended, I'll have mostly white painted walls with patches of gray pitted block and gray/tan(?) eroded mortar. If no repainting is to be done, is there any to make these obviously damaged areas in otherwise white walls look less ugly as I ready the house for sale? These eroded areas and the salts that flake off are an alarming turn-off.

  2. Hi, Alice. Unfortunatley, I don't have an answer for you. I'm posting with the hopes of trying to get other to reply. I have the same situation. I have a UGL (Drylok) sealed basement wall and efflorescence is still showing up on those walls. I'd like some assistance as well. Thanks!

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