How to stop efflorescence on concrete?

[rc1]

I have efflorescence occurring outside. I don’t like its look and am concerned it might over time damage the integrity of the concrete. What can I do about preventing it (ie painting etc as I’m already aware of reducing standing water) or improving its appearance?

[MitchellMc]

Hi @rc1,

You could try applying a penetrative sealer over the surface to prevent moisture contact with it. I'd suggest a product similar to Crommelin 1L Natural Finish Penetrating Sealer And Water Repellent; it's designed to suppress efflorescence. You'll want to ensure that you scrub off as much of the white salts/minerals residue as possible before applying the sealer, or that look will be trapped beneath. 

You'll need to coat the paving, concrete and grout lines with the sealer. Make sure it's one decent coat across the whole lot.

Please let me know if you have any questions.

Mitchell

[Flip61]

Can an Epoxy floor belaid over the Cromlins product

[MitchellMc]

Welcome to the Bunnings Workshop community @Flip61. It's brilliant to have you join us, and many thanks for your question about applying an epoxy coating.

Epoxy coatings are designed to go directly onto a porous surface like concrete. The Crommelins product seals the surface, so you can't apply an epoxy over it. If you have a sealer on the concrete at the moment, you'd need to entirely strip it off before going through the preparation steps for the Epoxy.

Do you have an efflorescence issue but also want to use an epoxy coating in the area? If you can supply some more details about your project, I trust our helpful members will be able to assist.

Please let me know if you have any questions.

Mitchell
 

[Flip61]

There is a small amount of efflorescence coming through the slab and I;k like to seal it and put something down to make it easier to clean, it definitely needs to be a non slip surface as the last thing I want is to come home in wet weather and slide into the wall. 

[MitchellMc]

The Crommelin 1L Natural Finish Penetrating Sealer And Water Repellent has a non-slip finish and will certainly allow easy cleaning @Flip61.

Efflorescence is caused by migrating moisture through the slab that brings salts with it. Epoxy coatings do not do well with moisture in slabs. The hydrostatic pressure can push them off the surface, so I wouldn't recommend you coat with epoxy paint.

Mitchell

[KellyL]

Hi Mitchell 

I have efflorescence coming through brick and mortar on the inside of my home. The negative wall behind it has soil behind it (like a retaining wall that was never waterproofed) and the soil cant be removed. I need to clean it and then paint it but I was told that it may eat away at the brick if I seal the brick with paint. So if I use this crommelins product, will it seal the brick and stop the efflorescence ready to paint? Or i found a product called efflock that mixes into mortar. Can I put this over crommelins, or use it instead of crommelins? Thanks very much 👍 Kelly 

[EricL]

Hello @KellyL 

Welcome to the Bunnings Workshop community. It's sensational to have you join us. 

If you are referring to the Crommelin 1L Natural Finish Penetrating Sealer and Water Repellent. You generally can't paint directly over the Crommelin Natural Finish Penetrating Sealer because it is a penetrating sealer designed to protect the substrate without forming a film. Plus, painting over it will probably result in the paint peeling off.

In regards to the Efflock product, I'm sorry but I am not familiar with this product.   

Can you please tell us why the soil can't be removed? Removing the soil and sealing the outside wall would be the most effective solution to your brick wall.

Eric