Extracting soda from soft bricks?

[Dean Heighington]

A friend had the front of her house Soda blasted, to clean up the brickwork. As a result, the soda was forced into the, very absorbent, soft red bricks and now keeps 'leaching out' of the bricks, every few days (especially after rain) to leave a white residue on the surface. The blasting guys have been back on numerous occasions to 'paint' the bricks with Malt vinegar which they said would neutralise and remove the soda staining. This looks great until after the next rainfall when it reoccurs upon drying.

Added to this situation is that I have now repointed the wall (see my previous post) and we're both concerned that the repeated vinegar application will react with the new pointing mortar and cause further problems!

Can anyone suggest a way of dealing with the soda in a better way than using the vinegar, or is it only over time that the stuff will 'leach' out? What about sealing the wall? Is that a no-no because it would trap the soda behind?

Look forward to any responses. Will also take this up with some brick cleaning chemical manufacturers and report back.

Cheers. Dean.

[NT]

You can solve it by doing nothing. Efflorescence will occur, and you can either brush it off or simply leave it, it'll go in its own slow time.

Its a no-no because it would result in freeze-thaw damage to the bricks, and is liable to create a damp problem.

Efflorescence is common on new builds. Relax.

NT

[Dean Heighington]

It's not a new build but circa 1880. However, I did thunk that only time would solve the problem. It just doesn't look nice as seeing she's had the wall 'cleaned!', repointed and new sash windows fitted!

[The Natural Philosopher]

Oh just leave it or pressure wash every few weeks till it stops.

Took about a year to finally stop oozing out of my freshly built chimneys.

[The Natural Philosopher]

yebbut its newly soda blasted!

[stuart noble]

I guess they used sodium bicarbonate, which is a known abrasive and, unlike sodium carbonate, isn't all that soluble in water. In any case the salt created by treating it with vinegar would be just as visible as the soda.

[NT]

so you said.

so we figured. As there's not much you can do about it, best do something productive.

NT

[Rick Hughes]

got to ask ... why did you choose soda blast in first place ?

Why not just plain pressure wash ?

You can solve it by doing nothing. Efflorescence will occur, and you can either brush it off or simply leave it, it'll go in its own slow time.

Its a no-no because it would result in freeze-thaw damage to the bricks, and is liable to create a damp problem.

Efflorescence is common on new builds. Relax.

NT

[stuart noble]

And have a boat out while you're about it :-) At least soda blasting is a dry process