salt in bricks or is it damp

[divingmoose]

Hi,
We live in a victorian house and one of the kitchen walls which backs onto the old coal house has developed a sort of fluffy dry peeling of the pain on the kitchen side of the wall. This has happened above skirting level and i wondered what is this and is it something to do with the coal house on the other side. Just to add that this wall and the whole kitchen was re plastered 2 yrs ago by the builder who renovated the house could it be something to do with the plaster.
Thanks Lee

 

[roughcaster]

Quite possibly. gypsum plasters are bad for absorbing salts/effloescence from the brickwork. It's always advisable to scratch coat older brick/blockwork, with a sand and cement render, with a waterproofer added to the mix. This would then be left to set and cure, then it could either be top coat rendered flush, and then skimmed with finishing,, or it could be brought out flush with Bonding plaster or Hardwall, and again finished with multi finish. It's worth checking for any cause of damp, eg, soil level outside to high, leaking guttering, bad pointing etc,, but i would say in your case, it sounds like salts leeching through the plaster.

 

[divingmoose]

Hi,
Thanks for the reply. Would this mean the only way to stop this is to remove the new plaster board and get it done again or is there anything else i can do with whats on all ready.

 

[roughcaster]

Is this new plasterboard?? how was it fixed to the brickwork, for example, was it dot and dabbed onto the old brickwork, or was it onto a timber frame,,, also, is the kitchen floor solid? Sometimes, if the kitchen floor is solid and the bottom of the plasterboard is touching it, it can draw moisture etc up from the floor.

 

[divingmoose]

Not sure how the plasterboard was fixed as we bought it after renovation but i would be quite sure it was dot and dab to be honest and the kitchen floor is concrete. The spots on the wall are in a couple of places and the paint has peeled of as if its gone like rubber and peels off.

 

[^woody^]

These salt crystals are caused by damp evaporating from the wall - either dampness within it or condensation drying off

 

[Nige F]

It`s a residue from the coal that was in the coal house - lucky it wasn`t a S*** House next door

 

[chappers]

As woody says it's damp as for finding the cause good luck we have a small patch by our back door that I have been trying to eradicate for 10 years now, basically I have given up and just give it a rub down and paint over every spring.