Paint peeled off bathroom ceiling

longwalks1

When we renovated our bathroom, the ceiling paint peeled off almost like it was wallpaper (it’s definitely paint). Was probably on there for 15 years or longer.  Now we have a newly ‘peeled’ ceiling ready to paint.

is there an undercoat or paint to use before we apply bathroom ceiling paint? The plaster is very smooth (as expected), we just don’t our new ceiling paint to not adhere properly. 

Browntoa

PVA glue , mixed with water and painted on . Then add top coat 

Mr.Generous

On new plaster a water thinned coat of paint for new plaster (used to call it a non-vinyl emulsion) or better yet a really cheap matt like B&Q value matt - which is a non-vinyl emulsion but costs far less than paint for new plaster. Water thin at about 50:50.

Basically the first coat needs to absorb into the plaster to bond, (the PVA water mix does same thing at 5:1) a decent vinyl emulsion doesn't do this, the vinyls are the tough wear layer, and as you found out can peel off like latex almost, if not bonded properly.

You might need a quick sand down, but where the paint is sticking it will be ok, just get the stuff off where its not bonding.

Edit - Yes as Grenage says a mist coat, I should have been clearer you thin it right down. If you use PVA its about 5 parts water to 1 part PVA - it works as a mist coat at that ratio. It will tell you this on the product. PVA has been used thinned by decorators and plasterers for years - I've used it - it works. 1 coat only - if you do a second coat it forms a skin and will repel the paint or peel off.

Grenage

PVA has no business on any surface you plan to paint.

Apply a mist coat and then paint.

pmartin86

Grenage said:

PVA has no business on any surface you plan to paint.

Apply a mist coat and then paint.

I've no idea why this keeps getting passed around. PVA should never be used on plaster before painting, ESPECIALY in a humid enviroment like a bathroom.

OP, please follow the excelent advice by @Mr.Generous

Doozergirl

pmartin86 said:

Grenage said:

PVA has no business on any surface you plan to paint.

Apply a mist coat and then paint.

I've no idea why this keeps getting passed around. PVA should never be used on plaster before painting, ESPECIALY in a humid enviroment like a bathroom.

OP, please follow the excelent advice by @Mr.Generous

I think you're confused.  Grenage gave the right advice, Mr Generous is advocating for PVA, which is wrong.  

I can almost guarantee that the reason the bathroom paint peeled off is that PVA was used as a mist coat initially, and acted like a barrier, preventing the paint from adhering to the wall.  

If it gets damp in the bathroom environment then it causes the paint to peel off.  Same happens with a subsequent coat of paint - the first painting can look fine but when you go to repaint the room, the PVA gets wet and the first layer peels off.  

Albermarle

On new plaster a water thinned coat of paint for new plaster (used to call it a non-vinyl emulsion) or better yet a really cheap matt like B&Q value matt - which is a non-vinyl emulsion but costs far less than paint for new plaster. Water thin at about 50:50.

This would make sense if you had a lot of plaster to coat. However for just a bathroom ceiling, easier just to thin down the paint you will use for the final coats.
The B&Q value stuff is cheaper, but not if you only use a bit of it, and the rest goes into the shed to be thrown out at some later date.