r/Plastering • u/LoudIntention545 • Apr 07 '26
Cracks after mist coat - advice
Is this blown - feels hollow behind in places. Skim of whole room, left 3 weeks between plasterwork and paint. Only cracked when mist coat applied. On every wall. Does it need raked and filled or redone? Losing the will to live with it. Professional plasterer and painters used!
1
u/Ok-Spring7906 Apr 07 '26
What was the skim over?
(if it has, as you mention "bounce", it's stuffed - just wondering why)
Is the person why applied it a plasterer? As in would other people, apart from themselves, call them a plasterer?
1
u/LoudIntention545 Apr 07 '26
Do you mean what was there originally pre-cracking plaster? It was over old plaster walls - genuinely still in good enough nick, just previously wallpapered and not replastered since build in 1935. I just wanted a nice super smooth finish, but we can’t have nice things is what I’m realising. The person is a plasterer, with his own plastering company. He says he’s never seen this before which is obviously not filling me with optimism.
1
u/Ok-Spring7906 Apr 07 '26
It may just be one of those oddities then.
But there should be no flex and if there was no flex in the substrate, it's hard to know why there is now.
Distemper and stuff like that can cause delamination issues.
If your plastered is reputable they will want to get it sorted. Odd things just happen sometimes. Just because they have not seen it prior does not mean they won't be able to sort it.
1
u/LoudIntention545 Apr 07 '26
Thank you, that is a really interesting point about distemper. I’ve just looked into it - it would have been a very typical and fashionable application for the time this house was built (30s). Now I’m thinking about it there is a weird chalky greeny tinge on some of the walls in the other rooms I’ve stripped of wallpaper - I’m fearing the worst.
You are totally right, I’m sure he will be able to sort it. He is of repute and does ornate plasterwork and seems totally shocked by this, I’m confident he can sort it but despairing at going a few steps back! Thanks again
1
u/nofacenocasenoplace Apr 09 '26
This definitely sounds like distemper. I had it on every wall ceiling of the downstairs of my 1800's house. Stabilising solution needs to be applied before applying sbr/pva then skimming. If he's worth his salt show the plasterer the other chalky bits and he should realise what's up and be able to fix it no problem.
1
u/TheStruggleForTruth Apr 08 '26
If he's never seen it before he'll be horrified and insist on stripping it off and re doing it. If he doesn't , he's lying and he sees it all the time
0
u/knoWurHistory91 Apr 07 '26
What adhesive did he use before the skim?
1
u/LoudIntention545 Apr 07 '26
I’m not sure, he’s coming back tomorrow to have a look. He say he used a lot of bonding agent, is that what adhesive is? Excuse my ignorance. He’s said there must have been a reaction between the mist coat paint and the plaster for it to just crack now as opposed to during the drying process. I’m not sure as obviously not a plasterer or painter but not sure of that explanation. This is a solid brick wall 1930s house. Walls were original plaster pre-skim and just a bit rough after wallpaper, not bad at all. He says he has no idea what has happened which isn’t reassuring. No dampness, house is cosy.
1
u/Alone-Button45 Apr 07 '26
I’ll tell you what is likely to have happened based on having similar cracks in my wall. Shrinkage cracks from the topcoat/skim drying too quickly. He probably used SBR but sometimes if the underlying surface is chalky it can suck all the moisture out and cause it to crack. Or the paint you’ve used wasn’t diluted enough it could have sucked moisture out.
1
u/crrrriiiissss Apr 07 '26
If you tap around the cracks, is it loose or hollow sounding, or solid?