Unexplained Damp Spot causing Paint Peeling

[mrrusty]

Does that Ronseal Damp Seal really work?

I've used it over some salt-loaded plaster which was growing crystals on my chimney breast, and so far it seems to have isolated the salt and stopped it growing and pushing the paint off. Still slightly early days - a few months since I tried this paint, but I feel I'm winning. I also had issues because the inside of the bricks on the sides of the chimney had been damp because the chimney was uncapped. Drying out and isolating seems to have stopped salt crystal growth. I have also seen a similar problem, to a lesser extent where dabs on dot and dab plasterboard had salts coming through where the wet dabs had drawn salt out which then leached through the plasterboard. My problems I'm sure stem from 100 years of coal fires.

My house refurb has been interesting - "damp" patches half way up internal walls which couldn't be coming from outside or the ground. So many theories out there.....

 

[JohnD]

If you seriously believe that the wall is sucking water out of the air, in one small spot only, that is not on a chimney breast...


Tape a piece of clear plastic tightly over the wet patch.

If the water is coming from the air, it will stop.

If it is coming out of the wall, it will not.