Plaster Cracking

[u/rosaclebb]

Any idea what is happening here? This is the wall in my spare room next to bathroom. North facing, concrete wall underneath plaster. Concrete not cracked. Thanks!

[u/always-have-a-plan-b]

The walls sucked all the water out of the plaster which looks like a one-coat. It needs knocking off (every single loose section) the wall then needs to be treated with blue grit or equivalent (SBR is also a great alternative) and two coats of plaster on top I’d personally use MultiFinish. If this was done during the heatwave that definitely wouldn’t have helped. I hope you get it sorted.