Hello, I had some walls replastered (in some places just reskimmed, and in others plastered all the way up from the brickwork). Now I am soon to paint the room and on close inspection I see a lot of very thin hairline cracks which run approximately horizontally across the walls (mostly no more than half length). They are so thin you cannot see them unless you look at the wall from around 5-10 cm away. Is this anything to worry about or is normal for new plaster? Thanks, Mark
That might - we love photos... Is there anything in that wall that could make this happen? Are there plasterboard sheet joints where these lines are? Were there any cracks/joints there before it was skimmed?
Photos attached. The work was done end of August, so heating would not have been on. Obviously it is now we are into winter. Some new cracks have appeared in last few weeks.
Based on the photos is this a major worry? If so I suppose I should contact the firm and ask them to take a look, though if it just dried too quick is not really their fault? But its not mine either because I was not running heating until October (work was done in August), and they did not tell me to keep heating off for months on end.
"Is there anything in that wall that could make this happen? Are there plasterboard sheet joints where these lines are?" The wall has had a damp proof tanking system put in up to 1.4 m. The cracks are both below, at and above this height. So it does not appear to correlate. "Were there any cracks/joints there before it was skimmed?"" None at all that I can recall.
I'm stumped, Shef. I don't really know enough about plastering to say much more. Also I can say is, it's nothing you've done. Was it particularly warm and dry in August (I can't remember that far back...)? If that was the cause - it drying out fractionally too quickly - then I think that's probably a good thing 'cos it's nothing more sinister! I would certainly contact them and ask about the best way to fill these cracks successfully. Personally I would like to do something to 'bond' the crack sides together first before filling. Not sure what to use, tho'...
Definitely get them back to have a look. You can get cracks when the block/brick, some (some bricks are vampires) sucks the moisture out of the plaster, this is solved by priming the wall before plastering with pva diluted 4 to 1. There is a chance the plaster might have failed & not properly bonded to the brick work, so it part company with the wall. Use to use Knauf high suction pimer some years ago to combat the high suction of some brickwork.
So the plasterer said these cracks are common when drying, and should be covered easily with a base paint coat. They advised filling lightly with Easifill if they still show through after that.
Total bs, yes you can get fine hairline cracks, but those ain't,background has sucked the moisture out of the plaster too quickly, drying too quickly due to heat,even using out of date plaster can causes problems.
June & July were the hot months this year DA, I remember that cos I was in your lovely neck of the woods in August for a couple of weeks and the weather could have been a lot better
Spot on. Being a bricklayer I'm not the best spread in the world, but I have learnt a few things about suction and old plaster over the years. Can remember doing a few plastering jobs when I was a lot greener and thinking I'd done a half decent job, and then suddenly all the cracks started appearing as fast as i could trowel them away.
Any hollow sounds when you tap the wall? When they re-plastered from the brickwork, did they dab on plasterboard or wet plaster with a backing coat? What did they plaster over on the re-skim parts? Was it wall papered before, any silk paint etc?
Looks to me like it’s been skimmed over old lath and plaster which is dead! Or unstable substrate underneath
"When they re-plastered from the brickwork, did they dab on plasterboard or wet plaster with a backing coat?" I'm afraid I have no idea, beyond knowing up to 1.4 metres cementitious tanking was added. "What did they plaster over on the re-skim parts? Was it wall papered before, any silk paint etc?" Matt emulsion paint I believe. My understanding is the re-skim was only done on a small fraction of the wall, the rest was fully replastered to full ceiling height (due to the old plaster being damaged from a water leak, which was first fixed my plumber). "Any hollow sounds when you tap the wall?" No it doesn't sound any different to any other wall I have tapped. This would be a very obvious sound difference to hear (i.e not so subtle an amateur might not spot it)?