salt comin through new plaster

[kitp]

I have recently had my kitchen walls skimmed and have found a couple of areas (which dried but remained dark after plastering) are pushing out salt, ruining my paint work. I have heard so much conflicting advice about using oil based paints/ stain blocks etc I dont know how to fix it. I painted it with wood paint and then emulsion as advised but this hasnt worked. Please help.
Thanks Kit

 

[joe-90]

You've got water permeating from the outside somewhere such as a leaking gutter. You've got to fix the problem otherwise you'll never get is sorted.

 

[Zampa]

As Joe says....the water is causing the Alkali in the plaster to re-activate and the consequence is the salts (effloresence) on the wall.

You need to stop the source first then brush the salts off dry and give it a coat of alkali resisting primer sealer...forget the old wifes tales about gloss, PVA etc.

 

[D.S.D]

yep, gloss oilbase undercoat zinser and stain blocks will only work on cured water problems when the stain bleeds through your emo. You have to cure the problem at its source. Is there any pipes behind the area that you know of??? Gutters, as joe says is a favourite, as is the felt from the roof being overlong and going behind the gutter and even in some cases behind the facias. You need to stop it at its source or you will never be able to cover it up. Sorry. Come back and let us know what you find

 

[kitp]

Hi, thanks for your advice. There is no water supply on the other side of the wall, the salt seems to be coming through where the plaster was particularly thick (eg; between two electris sockets). If I paint it with sealant will it then come in elsewhere? Thanks Kit

 

[Zampa]

Possibly..or the sealer will flake off too.