plaster pealing when painting

[clive.tiller]

new plaster starts pealing when I paint

[Andrew Gabriel]

Do you mean the plaster is peeling, or the paint is peeling? Both can happen for different reasons.

Need more info on the history, surface preparation, and type of paint.

[Dave Baker]

Exactly what sort of pealing noise does it make? Like a church bell or more of a squeak?

[Weatherlawyer]

It sounds like the plaster used was past its sell by date. Old plaster, stu ff that has been on walls for years, can be subject to deliquescence. That is crystals of magnesium sulphate come out of it with condensation.

But if the bag of plaster that was used in the mix had been hanging around opened too long or was a batch left on the bottom of the pallet in the lock

-up so long that it got damp...

I don't know what else would cause the plaster to fail, maybe the substrate was damp. Take a look at the contract you have to see if the contractor ha s to rectify it. But you may be better off just removing it yourself if it comes off so easily.

It is true that the first coat of paint needs to be thin to allow the plast er to dry properly. Contractors trade paint is like that and goes to dust i n a few months. That is a slightly different problem and can be cured with a fresh coat of thin paint. Followed some day or so later by a couple of co ats of good stuff.

It has just occurred to me that I recall someone trying to paint a new hous e in a freeze. The heater he was using was supplying even more condensate. That would have been fun. No idea what happened next though.

[Andrew]

What do you mean by 'plaster' ?.

Have you been making good defects with crap like polyfilla ?, or is this a properly skimmed job using gypsum plaster ?.

Have you had old walls skimmed without removing all the old paint first ?. Or even (as I have seen) skimmed over layers of old wallpaper ?.

If so, and it was vinyl silk complete with greasy finger marks and blue tack residue then I'm not surprised that the new layer has parted company.

[Andrew]

Believe me, trying to skim walls using out-of-date plaster is almost impossible. It goes off far, far too quickly, even more so when skimming over old plaster. Been there, tried it.

The only use for old plaster (or old Wickes fine surface plaster) is to attach support meshes and outside edge end stops and the like, where you want it to set quite quickly.

[Brian Gaff]

Perhaps its been to sunnier climbes? Brian

[Andrew Gabriel]

I keep a bag around for filling chases.

[Sam Plusnet]

I suspect it's ringing wet.

[Bob Martin]