Repair paint flaking off plasterboard ceiling above shower

[groucho]

Hi
Got a big problem with matt white paint bubbling, then flaking off the plasterboard ceiling above the shower cubicle after two years of abuse by our children (Long showers with window closed!) Where it has flaked off it has revealed the smooth brown plaster beneath it. SEE PICTURE

Unsure how to proceed

Found conflicting advice on internet sites!!!

Some advocate using a PVA/WAter mix as a primer/sealant then painting on top.
Others say NEVER NEVER use Pva/water as a primer on plaster as it traps the water ( I'm thinking though that this exposed plaster isn't new so it has dried out yeah?) . This second school of thought suggests using breathable matt emuslion as undercoat then a water resistant matt emulsion as top coat.


Advice from anyone with knowledge or experience of remedying this problem would be grately appreciated before even more of the ceiling comes down.

Photo included - odd angle but the flaking part is the ceiling!

Help


Groucho

 

[TheDec]

groucho.

Before we go any further listen to the others and Never Never use pva.

So your matt emulsion is flaking and has revealed bare plaster skim, this could have been caused by the humidity factor, the wrong paint system, and bad prep. In simple terms the failiure of applying a mist coat to seal the skim prior to applying your finish coats.

Matt emulsion is not in the norm a recommended coating for areas of high steam and humidity, frankly these paints are not up to the job.

Eggshell paints are both designed and formulated to give you excellent results in such situations.

Going now to prep and combining the correct product I am going to point you in this direction, scrape off all loose and flaking paintwork, sand hard to break through all existing coatings and mist any areas of bare skim.

 

[TheDec]

Sorry mate.

People talking to me, aint finished yet, there are two paints that are now proving their worth above all others for your situation. Dulux Trade Fungicidal Eggshell and the same in matt. If I have in any way confused you here please forgive me and accept my most sincere apology.

I'm blaming here the chatter of others and not the numerous cans of speckled hen.

 

[groucho]

Thanks Thedec for such a swift reply!

Please explain to this enthusiastic but amateur DIYer what a "mist" coat is?

"Sealing the skim"? Is this the plaster?

Lastly since a lot of the ceiling paint is not affected by the humidity can I just key it with sandpaper and paint the egg shell on top of this emulsion so it all blends in?

Thanks

 

[TheDec]

A mist coat is just a coat of thinned emulsion that should be applied to bare and exposed skim, in answer to your next question, yes it it should be ok if the remains of the existing paintwork shows no sign of breakdown.

Thats it for now mate.

A very piddled

Dec.