Efflorescence?

[Harry Bloomfield]

A few months ago, I repointed our double brick (no cavity) utility wall. It desperately needed repointing. Now, after weeks of dry weather, I am seeing lots of efflorescence on the outside face of the wall. I'm wondering if this might be due to the brickwork drying out, forced through the brick face, rather than as it was before, through the bad joints ? It all simply brushes off.

 

[Koolpc]

Rub cream E45 over it all. Repeat for several months.....

Woof!

 

[^woody^]

If it is coming out of the joints then it was either the sand you used, or maybe if the wall was already saturated before repointing or if it was soaked too much as part of the repointing.

If it is coming out of the bricks, the wall was saturated (possibly a too-strong repointing mix) and salts are emerging from the clay.

Either way, its potentially dry brushing for the rest of your life or it may randomly stop

 

[^woody^]

Rub cream E45 over it all. Repeat for several months.....

Woof!

No, that's for cracking

 

[jj4091]

Everything I have read about efflorescence suggests that is salts in materials that gets washed to the surface and is left behind when the moisture dries out. By that theory it could be either the bricks themselves or the mortar you have used for pointing. What I find difficult to believe is the fact that a section of our garage roof which was cast in flat concrete in 1946 is suppossedly still giving up these salts. Even 26 years after a pitch roof was installed over it, the efflorescence still regularly appears even after brushing it off. This to suggests that it is something in the atmosphere that is condensing on the surface rather than being expelled from the concrete