Bathroom ceiling - help please!

[Mouikey]

Quick backstory...

House built 1990's, big internal burst pipe flood 5 years ago, whole house replastered and upgraded. We bought house about 4.5 years ago.

The painting throughout the house was poor, but we have lived with it. However the bathroom had a crack in the ceiling. We painted over using a bathroom paint within our first year - all good. Last summer the crack returned so we filled it and repainted it. By Christmas notnonly had the crack reappeared but the paint started flaming.

I decided to rub it down, flexibly fill the crack and repaint - couple of hours job! No such luck! the paint flaked in massive chunks right back to the plaster.

Went to the hardware shop who suggested we remove all the paint (this has been worse than labour) seal using a diluted pva (2 coats, which should also take care of the crack as its hairline) and then repaint.

All good, but absolutely everywhere I looks says don't used pva to seal as paint won't then stick to it (we were planning to use a vinyl/bathroom paint). The crack isn't big and I don't think filler will actually work.

Can anyone give some advice with regards to the pva and what paint I should use over the top (will bathroom paint be ok?). I can buy the paint from the guy who advised me so would assume he knows what he is doing!

Help, I don't want to make things worse! (Sorry for long post!)

I've used pva coats for different situations then painted over and has stuck ok.

I would consider the cause before covering up the symptoms.

Have you taken a few moisture readings of the plaster over a period of time?

And how big and sort is the crack? Is it just resettling following the refurb or something more?

Thanks!

So the crack is probably just settlement, it's just wider than a hairline crack but quite long. When feeling the plaster you can barely feel it, I expected to find filler in it from our previous diy outings, but nothing (and I'm not surprised it's so thin!)

The hardware guy thinks the problem with the paint stems from it not being sealed as (especially around the crack) it came off in huge chunks!

He suggested a 1:3 ratio for the pva. What type of paint would you recommend?

Thanks for your replies

Oh I don't think there is a moisture issue, we have an extractor fan and window kept on the latch.

I think the fundamental problem is the base ceiling has lost its integrity, so whatever you put on top is going to crack sooner or later unless it's a layer of rubber or something. So what you really need to do is cut out a rectangular area of ceiling around the crack and loose are back to the joists, which will hopefully not be the whole ceiling. Then screw new plasterboard to the joists, tape the old to the new, and then at least fill that area, but ideally skim the whole ceiling.
As a bodge you could try finding the joists and peppering them with screws, but if the plasterboard is crumbs it won't help much.

Although q, is the crack in a straight line or going here and there? If it's straight it could be the joint between plasterboard which might suggest movement above or lack of taping the joins.
Is the loft above used a lot or heavily loaded?

We have lots of cracked ceilings and the advice was always to overboard and replaster. We have systematically done this on most of the ceilings and so far so good, no more cracks.

If you do go ahead with the pva, our decorators used dulux super grip primer when painting our laminate/melamine kitchen (stop gap until we can replace it). They said it will stick to anything.

I wonder if there is a leak from the refurb or something that is keeping it moist and effecting the paint. You can pick up the pronged testers for £10. I would do that to check the levels for 2 weeks and if is dry and consistently so (don't do just after a shower) then it is prob just cause the existing plaster is old.
As johnd2 says the plaster sounds like it it is tired and it may be easier to draw a plasterer quote how much to replace.
Overboarding would be the cheapest way but if there is a leak above you will end up having the same issue eventually.
I always use dulux bathroom+ paint as it does seem to keep a nice finish and hold mould back even in damper places like bathrooms.

Thanks all, I wouldn't have said the plaster is old (just 5 years if that!) and there are no leaks that I can see - in-fact the plaster looks in great condition apart from the hairline crack and dents I have caused scraping the paint off!! There doesn't look as thought there are water marks

I think Johnd2 may have cracked it (I don't know if pun intended!) because the crack is straight, I do wonder whether they didn't tape the joints. The loft is above and we boarded it about a year ago (not heavily used, but has a 'fair' amount of stuff up there).

So I think the idea of replastering or overboarding may be an overkill in this instance (although I imagine I will be proved wrong!). I shall try the PVA thing, followed by the Dulux Primer and then Bathroom+ paint.

Does that sound like an OK(ish) plan?