Customer has a bedroom in an extension where the mortar appears to be staining the paint - you can see a darker shade that replicates the joints in a blocks. I assume that one of the Zinsser products will deal with it but what has caused it? Anyone have an idea
Does the customer use a lot of candles in the room? Experienced something similar where candle smoke/smut was sticking to the wall (north facing first floor room) where the plasterboard had been dotted and dabbed onto the brickwork. Concluded that it must have been something to do with the temperature difference between those patches and the rest of the wall. Could be something like that?
I've experienced something similar as Bod and Jimbob. 1. An old terraced house had been gutted, dot and dabbed and turned into offices. When it needed repainting (after approx 5 years), in a couple of the rooms, upstairs and downstairs, there were dark patches where the dabs where. I undercoated the entire affected walls (x2) before applying vinyl matt. Been done three year now and still good. 2. Did a bedroom last year where the mortar joints where showing on the wall (external). Did the same, 2 undercoats. Not heard anything back as yet, (customer well picky so would be on to me like a shot if it came back). Could both cases be caused by from cold/damp being drawn from the outside and being bridged on the dabs and mortar joints? If so, I suppose it will eventually return but as yet both jobs have been ok
what has caused it? Anyone have an idea We had the identical prob. As jimbo says, it could be candles and where we were, this guy smoked cigars.Still not sure. Anyway, Bod, ... have the cavity walls been filled with insulation. ??
Could be where a chimney breast has been removed and the soot stained morter is bleeding through, seal with Zinsser Cover Stain or Bullseye 123.
Fortunately didn'tt get the job, some tight fisted scot who was consulting tables for exact cost per sq meter, and wanted the quote splitting every which way.