What are these encrustations on brick?

[Min88]

and how can I get them off!

Not on other bricks around the house as far as I can see.

Other side of the wall is the living/dining room with concrete floor.
Cavity walls with insulation. Encrustations seem to be below DPC

I’ve googled but nothing seems to match up!

 

[Nige F]

It's efflorescence - see google

 

[JP_]

Rising damp - but stopped by the damp course. Water is drawn up into the bricks, and the salts in the water are left behind when the water evaporates.

 

[Min88]

@Nige F ah thank you! It just looked so much more crusty than the google pictures!

@jonbey ah I see, so just normal then I guess? There was quite a lot of overdrawn grass/brambles right against the brick so don’t know if they made it damp!

Any ideas to get it off without damaging brick?

Thank you!

 

[JP_]

Just leave it? It should dissolve away in time, when it rains etc.

Some tips here:
https://www.nitterhousemasonry.com/tips-advice/what-is-efflorescence/

Some of the best ways to remove efflorescence include:

1) Pressurized Water: Applying pressurized water may dissolve efflorescence quickly. If you use water, dry off the water from the building material after application. If you fail to remove the water, crystals may remain that can cause efflorescence to reappear.

2) Diluted Vinegar: If you’re in a pinch, using household diluted white vinegar can be used on efflorescence. It’s less harmful than industrial chemicals and you most likely already have vinegar in your kitchen.

3) Brushing: With a strong brush, you can remove efflorescence with ease.

Removing efflorescence can be quick and simple. In fact, efflorescing salts are water-soluble, which means efflorescence may disappear on its own due to normal weathering.

To clean efflorescence off brick, it is crucial to complete this task in warm, dry weather. At this point, moisture may bring additional salts to the surface of brick, and the salts can be removed by dry brushing.

 

[^woody^]

Just leave it? It should dissolve away in time, when it rains etc.

Some tips here:
https://www.nitterhousemasonry.com/tips-advice/what-is-efflorescence/

Some of the best ways to remove efflorescence include:

1) Pressurized Water: Applying pressurized water may dissolve efflorescence quickly. If you use water, dry off the water from the building material after application. If you fail to remove the water, crystals may remain that can cause efflorescence to reappear.

2) Diluted Vinegar: If you’re in a pinch, using household diluted white vinegar can be used on efflorescence. It’s less harmful than industrial chemicals and you most likely already have vinegar in your kitchen.

3) Brushing: With a strong brush, you can remove efflorescence with ease.

Removing efflorescence can be quick and simple. In fact, efflorescing salts are water-soluble, which means efflorescence may disappear on its own due to normal weathering.

To clean efflorescence off brick, it is crucial to complete this task in warm, dry weather. At this point, moisture may bring additional salts to the surface of brick, and the salts can be removed by dry brushing.

No you cant remove efflorecence by washing. It just gets reabsorbed back into the wall, and comes back once evaporation occurs.

 

[^woody^]

As the deposits are crusty, its less likely to be efflorescence and more likley to be a calcium or silicate salt and these could be chemically cleaned. But you need to know if this is the cause first.

Looking at the mortar joints there is a damp issue there and it could be other ground salts too, but the DPC is doing it's job.

 

[^woody^]

Rising damp

No its not rising damp either.

Rising damp is a specific problem, and is not just dampness in a wall. That wall is naturally damp as it's in contact with the ground, and that is not an issue.

 

[Min88]

Thank you @^woody^ How would you go about determine if it is those salts? What does chemical cleaning involve? Very novice here!

 

[Min88]

@^woody^ Out of interest it’s not sulphate attack is it? Only we have a concrete floor the other side with some damage/dips in it

 

[^woody^]

It would need to be sampled to see what the salts are, and then a suitable solution recommended. The chemical cleaning would involve folowing the instructions of what ever chemical was used and that would depend on what salts they are, it can be different.

 

[^woody^]

@^woody^ Out of interest it’s not sulphate attack is it? Only we have a concrete floor the other side with some damage/dips in it

It could be. Sulphates affect the cement in concrete and mortar, so if the floor is experiencing it then so can the walls.

If that is the case, and the source is the fill below the floor, then removing that properly can remove the sulphates down to a manageable level.