having some problems with plastered wall...

[brooklyn07]

I've just had part of a wall plastered around where an opening was created between two rooms. The plaster doesn't go across the entire wall just around the edges where the opening was made and has been thinned out to blend in with the wall.

I have waited 2 weeks before attempting to paint and the walls were very light pink. I started off with a mist coat.. however, as the paint was being rolled across the thin parts, the plaster started to bubble, flake and then came off with the roller...

I waited a couple of days until that had dried and tried again but again, the thinner parts of plaster were coming right off the wall... I scraped it back a little and whole chunks have come off and fallen off the wall.

I'm reluctant to mess with it further and have called the plasterer who has said it must be something I've done wrong as the wall was bonded right up to where the plaster is very thin.

there was paint on the existing wall and lots of nicotine. Is there a chance he hasn't prepared the wall properly or is he right in that its something I've done wrong?? I've painted plenty of other walls that have been plastered and have never had this problem, although none of the other walls I've ever painted have been thinned out to match an existing wall so i'm not sure if this makes a difference...

any ideas please??

 

[roughcaster]

This IS the plasterer's fault. Although he said he bonded the area he plastered, he probably went out beyond that area to "feather out" the patch. That's the problem when an area of wall/ceiling has been just patched and feathered. For the plasterer to say the problem is your fault is not true, it's his plaster that's came off, so it's "his" bad prep that's caused the problem. Get the whole wall prepped and skimmed by a "proper plasterer".

 

[joe-90]

This is a common problem. The cause is this:
Plaster sets and becomes hard by chemical reaction. If the plaster skim is too thin (as in feathering) then the water content dries out before the plaster can set - so is in effect just dry (unset) powder. The easiest and cheapest way out it to water down your paint 50/50 and apply by brush several coats. Then let it dry. Sand as necessary and use some cheapo filler to make it smooth. Then apply the 50/50 paint to the new filler. When dry you can paint it as normal.

 

[stevethespreader]

I've feathered skim down hundreds if not thousands of times "we all have" its poor prep on top of existing paint also if it was heavily nicotine stained it could have done with sugar soaping

 

[brooklyn07]

Thanks - he definitely didn't wash down the walls first and theres a thick layer of dust on the one wall right up to where its feathered out.. there were 3 separate walls in total that needed "making good" and they all have feathering. The one wall I have left now because it's just cracking and falling off the wall but only where he's plastered over the previous painted wall... where the gaps were in the wall and the plaster is thick this is fine so I assume its because he didn't prep the painted wall properly.
The opposite wall I followed joe's advice and have painted on several diluted coats of paint but again at the very edges its starting to come away. the one remaining wall I haven't touched with paint and I'm reluctant to.

if he comes back to sort it out should I be paying him if I ask him to do the entire wall rather than feather it out as I don't know if I trust it to work now....

 

[stevethespreader]

Joes advice was to give it a mist coat of 50/50 then use a filler to snag which would work and if out onsite this is most prob how it would be snagged its an easy job tbh, should you be paying him to skim the whole wall? That's a tricky one because you shouldn't be paying him to correct his work he may ask extra for the whole wall though

 

[stevethespreader]

What paint is it shiny?

 

[brooklyn07]

the paint on the existing wall is shiny, im pretty sure its silk... he is coming back tomorrow to sort it so I think in preparation I will wash down the walls that are next to the plaster and including the parts where the plaster has fallen off and give it a bit of a sand....

 

[stevethespreader]

Yes rough it up a bit Also its best to use strong PVA on such paints why don't you post some pics up of what its like now and then when he's finished make note of PVA he's using and what strength

 

[brooklyn07]

Ok so it's been repaired...The rest of the wall wasn't plastered just the bits that fell off but it doesn't look like regular plaster it's some sort of light brown/beige stuff. .any idea what it could be and do I treat it the same as plaster i.e waiting a week and then mist costing?