Paint peeling in shower room

[bawbster]

Few months back wife decides it's time for the en suite to be painted again, used the usual Dulux bathroom paint as have done the previous 3 or 4 times it has been done. This time though, the paint has started to crack and peel. Sanded off the cracked paint (didn't fill it) repainted and it's happened again. I've always painted over the previous paint with no issues but obviouslt this time there is. The window is always open and the extractor is always on for a shower and left on for a few minutes after.

Other than scraping and sanding, what can I do to prevent this from happening again?

Cheers

 

[Wayners]

Condensation.
Run a dehumidifier outside for a few hours every evening to dry out.
Extractor and opening windows helps but won't fix

 

[bawbster]

Condensation.
Run a dehumidifier outside for a few hours every evening to dry out.
Extractor and opening windows helps but won't fix

Any idea why condensation would cause this after all this time?

 

[foxhole]

Opening window cools room which needs to be warm long enough for fan to do its job.So no surprise it’s bad over the window?

 

[Wayners]

One theory.
Some condensation forms but it don't cause a problem. Paint degrades though and starts to lose adhesion but looks fine. You hit it with fresh wet paint and the damp pushes off the old paint.

 

[accelerator]

I would propose/guess it's something to do with the surface you're painting onto. If it's water-based bathroom paint, then whatever you are painting it on to needs to be able to absorb it a bit. I would say the problem is caused by insufficient surface preparation, so you need to investigate what surface you have, and how to prepare it for painting on whatever type of paint you are using (I'm guessing that's water based).