White Crystalised Substance All Over Walls In An Old School...?

[joko]

I have just started a job in an old school and the room we have has in 2 corners of the room an area of some kind of deposit on the wall .. possibly like it may be growing - its like rock salt, crusty, crystalised patches all over the walls ... the paint underneath has bubbled up and flaked off, its almost like its coming from the brickwork and pushing its way through the paintwork...

and the room also stinks and me and my assistant do not feel too well now ... just 'off', like we are coming down with something.

can anyone advise what it is and what we should do about it?

If we arranged for it to be cleaned/scraped off, disinfectanted etc, where or who would we go to to get it done, in the Liverpool area?

thanks

[carrust]

http://www.delawarequarries.com/cleaners/efflorescence.html
It looks as though the room has a damp problem.

[joko]

Thanks carrust - thats exactly it - thankfully it is safe and whatever damp there was has been sealed off

however, it doesn't explain the horrible smell - cannot figure out where its coming from!

[The Builder]

Good link from Crusty there, Joko.

Old school, so possibly solid brick construction (no cavity). Dampness in the wall is migrating through the plaster. The smell is likely to be deteriorating plaster.

I know you won't be involved in the remedy, but there are two basic ways of dealing with it. Either a barrier is put against the bare masonry then replastered (tanking), or the plaster is simply replaced with a traditional lime plaster that allows passage of moisture without plaster " spalling". This is being done quite often now.

The link explains how to treat it, but in time, it is likely to return. The problem is inherent.