White fur inside wall of garage

[Jetsetwilly76]

A few years ago I put a false floor into the garage to use the room. Beneath it I put down damp proof sheeting. I then used tanking paint to paint the wall up to the damp proof course sheet level.

A few months ago this started to happen, just in this corner. I assumed the outside might be to blame, so repointed the mortar on that corner but the issue continues.

Looking to find the cause and remedy please

 

[foxhole]

Looks to be effervescence , caused by damp washing thru the salts in the mortar .

 

[Deleted member 174758]

Efflorescence - effervescence is what your Sterident does!

 

[foxhole]

Efflorescence - effervescence is what your Sterident does!

Dam auto correct.

 

[Jetsetwilly76]

Thanks. Can it be stopped?

 

[foxhole]

Suggests you have damp problem which needs sorting first then the salts coming thru will eventually stop ( but can take months).

 

[Jetsetwilly76]

Is in the garage extension. Guess I need to get someone to look at it? No easy fix? Considered using some kind of exterior water repellent but could that trap the water in the brick?