Flaking paint on bathroom ceiling

[DIYspanner]

I moved into a house last year which had been painted through with what I presume to be trade white emulsion.

I noticed a bit of paint peeling off the bathroom ceiling above the bath so I scraped and sandpapered the patch then painted the ceiling with Dulux bathroom paint. It started to peel again and scraping, I can see the bare ceiling.

If I scrape the entire ceiling, what is the best product to apply to the bare ceiling before painting on emulsion again?

Thanks

 

[JohnD]

Does the bathroom extractor fan work well?

 

[DIYspanner]

Does the bathroom extractor fan work well?

Yes, no bother with the ceiling mounted fan. The ducting runs in the attic and out through the roof.

 

[JohnD]

That's good. If the extractor works well, and you use it during and after each bath and shower, and the bathroom ceiling is well insulated with no gaps, it should not suffer severe condensation and damp. Scrape off loose material, ensure it is clean and dust free (a coarse damp towel is good) and apply at least one thinned mist coat of emulsion before topcoating. I find vinyl silk is good, but the slight sheen shows up irregularities so you might prefer matt. If it is liable to be splashed you can use an acrylic paint, but this should not be necessary on a ceiling and IME a good finish is more difficult

New builds and new plaster are usually painted with non-vinyl matt, which is not durable or water resistant. Very old houses may have unsuitable coatings.

 

[opps]

Although I am a decorator- she what scowls at me decided to get someone else to repaint our downstairs shower/wc. They used regular emulsion and filled where an internal shower wall used to be. In time the emulsion started flaking off. I sanded it back, filled and used waterbased eggshell. It has been fine for the last 5 years.

Regardless of how effective an extractor is, unless you have really, really high ceilings, you will probably have some condensation on the ceiling. Waterbased eggshell will prevent that condensation from penetrating.

 

[ant2]

Wondering if you painted the ceiling too soon and it hadn't fully dried out from the condensation issue prior ?
i.e I would try again after you sure the plasterboard is completly dried out or use a primer like Zinsser bin.
My main bathroom is done in a zinsser perma white, which seems to do the trick for moisture.

Incidentally I had our other bathroom re-skimmed and painted last year and they only applied a Dulux Vinyl Matt, I noticed over the past month the ceiling has cracked quite a bit right above the shower like yourself.
I tested even a few minute shower with the window open and extractor on and you can feel the ceiling gets very damp with moisture with this cold weather (cold ceiling) and with repeated exposure every day, I am not surprised it has cracked the paint and there is not much more one can do with an extractor and window open, it still won't stop steam sitting on the ceiling.
I am going to get this re-done in Zinsser Perma white once the weather picks up.

 

[JohnD]

I tested even a few minute shower with the window open and extractor on

Extractors work better with the door and window SHUT.