DIY Doctor UK DIY Forums

Hello everyone!

I’m hoping the forum's expertise can help me resolve this. It starting to drive me nuts!

So, we’ve had an extension done. Plasterer came in. I left it a week, plaster turned a light colour and looked set (as per internet pics). I then applied x1 mist coat (80% paint 20% water) of white Matt. Left to dry then another coat of white Matt. Then 2 coats of the following;
Ceiling - white,
1 wall - dark green,
3 walls - light green.

The ceiling and dark green wall - fine, no problems. 2 of the light green walls have patches of cracking on them, the patches are in the inside of the window frame and in a corner exactly where the walls meet.

The ones in the frame appeared after the first coat so I scraped them back to the plaster or white coat then re-applied the coats is taken off. Then I put a 2nd coat on and now new cracks in the corner have appeared and the previous ones have come back. What am I doing wrong?!?

Hi,

I was wondering if you found out what caused the problem?
We have a similar issue.

The room was newly plastered. We waited 2 weeks before applying the mist coat and then first coat of paint. Ceiling and lathe/plaster internal walls are ok, but the external wall has severe paint flaking.
This is a 1907 build house and external wall is not cavity.

We've tried a second time with 2x mist coats, but same result.

We don't know if it's temperature, or the plaster on that wall needs longer to dry. Any hints would be useful.

Thanks