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Plater turning white, rusty nails and damp patches
We recently bought a mid-terraced house and are having some plastering work done. Previous owners are not very forthcoming with establishing when any work was done in the house, so can't provide much background except what we have done so far.
We had a room re-skimmed just over 2 weeks ago and plaster has started turning white especially on the chimney breast. Is this to be expected? If it's not what could be causing it?
Plasterer has banged the picture rail nails into the wall and small circles are showing where the nails are. Will they also show through the paint? Can this be prevented?
One small re-skimmed area in the kitchen corner (inside wall) still has brownish patches? Outside wall has been plastered (cemented?) at some point. Could there be a damp problem and would the outside work be causing damp problems?
Most socket covers were left in the wall and cannot be opened without breaking plaster. Should the socket and light covers be removed when skimming and skim applied below so that they sit on top of the skim?
Regarding the white patches without seeing it its hard to say but it shouldn't be anything to worry about. The rust will show up your best bet is to hack just enough to get the nails out the wall then fill it with poly filler and sand it flat. Before skimming all sorts of sockets, radiators etc should be taken away from the wall. Does the external rendering where you suspect damp have cracks in it? If so, then it is most likely that is how the damp is coming through.
Hope this helps.
Answered 24th Apr 2013
If the wall has any form of damp hidden within, then any metal nails etch being hammered in will result in stains coming through, use a good quality stain block on the areas and this will resolve that issue, I always use the zinnser products
These can be found in most paint outlets, even b&Q.
The brown patch does sound like a damp issue, but it could be trapped moisture. Maybe hire a dehumidifier, as not sure about your weather, this damp air doesn't really help drying times, and treat the area with the same stain block.
Plasterers can sometimes be lazy and not remove the covers, yes in an ideal world they should be pulled away so the plaster sits behind, but if you decide to replace try cutting down the edge with a knife (Stanley not kitchen) to help prevent to much coming off, and apply some filler to affected areas and slight behind the plugs.
hope this helps
Answered 5th Oct 2013