Bathroom ceiling mould and peeling: how to restore

tired_dad

as per subject; kids taken to v hot and long showers without opening windows. Got paint peeling and mild mould on there. I would appreciate advice on the steps to restore? What products would you use and in what order? Thanks in advance

web0z

Hi I would scrap the peeling paint off fill with filler and apply two coats of this https://www.thepaintshed.com/zinsser-perma-white-matt
and allow 24hrs before having another shower.
Just to let you know i am a decorator to the trade.
either that scrape , fill and undercoat effected areas and two coats of emulsion but I would recommend the first option.

Emmia

The Zinsser paint is excellent. (Perhaps get the kids to do the redecorating)

Could you install an extractor fan with a humidstat in the bathroom, linked to the light that will help remove moisture even if the window is shut?

tired_dad

web0z said:

Hi I would scrap the peeling paint off fill with filler and apply two coats of this https://www.thepaintshed.com/zinsser-perma-white-matt
and allow 24hrs before having another shower.
Just to let you know i am a decorator to the trade.
either that scrape , fill and undercoat effected areas and two coats of emulsion but I would recommend the first option.

when you say "fill" may I ask what you mean? 
There is darkish mould there. Your saying just paint over it with 2 coats of perm white will make it disappear? No undercoat or primer needed?

Emmia

tired_dad said:

web0z said:

Hi I would scrap the peeling paint off fill with filler and apply two coats of this https://www.thepaintshed.com/zinsser-perma-white-matt
and allow 24hrs before having another shower.
Just to let you know i am a decorator to the trade.
either that scrape , fill and undercoat effected areas and two coats of emulsion but I would recommend the first option.

when you say "fill" may I ask what you mean? 
There is darkish mould there. Your saying just paint over it with 2 coats of perm white will make it disappear? No undercoat or primer needed?

I'd wipe it over with a bleach based mould killer first, let that dry and then scrape off any loose paint, then repaint with the Zinsser.

When I used the Zinsser I bleached to kill the mould, undercoated with the Zinsser 123 primer, then gave it two coats of the Permawhite. 

Edit: the paint is fantastic, but really eliminating the mould did need a better extractor fan with a humidstat.

tired_dad

I have inline extractors in the attic. Not sure you can get those with humidistat?

ThisIsWeird

Hi TD.
So you do have an extractor in there. How effective is it? When you hover a sheet of bog roll under it, how close do you have to go before it gets sucked up against the vent grill?
Where is the vent grill in relation to everything else - the shower, the window, the bathroom door? It may be that opening a window won't help in any case.
You can buy humidistat sensors to fit separately to control the fan, but it's not essential - it won't make the fan more effective. Instead, just leave it running for as long as needed until the room is dry - if that's a half hour or even more, so be it.
If the fan just ain't good enough to cope - if it seriously streams up in there - then also consider upgrading it to a more powerful model. And make sure the bathroom ceiling has plenty of insulation over it - you want it as 'warm' as possible.
If that doesn't help, if the room still gets far too steamy, then you may need to curtail the long hot sessions, but 'good luck' to that...
How to sort the existing damage? It's a pain, 'cos any paint that's lifted or peeled is now no longer adhered to the board, and needs removing. This will likely include surrounding paint, more than you suspect. Sometimes it all seems to be removable, as you scrape away the 'loose' stuff, it becomes clear that it could all come off :-( You'll be there for hours...
With luck, only very isolated patches are lifted, and the rest still secure. What I have had to resort to in the past is to run a craft knife blade gentlat around a loose, raised patch, and then scrape to that cut line. That way I've given it an end point, where I know the rest isn't perfectly adhered, but 'good enough'.
Anyway, you will at least end up with paint 'edges', a visible step between the still-remaining paint, and the bare board. Two ways to tackle these - one is to sand the surrounding paint until the edges are sufficiently 'feathered' down to be hidden under fresh paint, and the other is to fill the missing bits using 'fine surface' filler, and sand it flat and smooth, usually the best method, certainly if the paint layer is multiple, or thicker.
What I've also taken to doing is to first SBR the bare board to seal it and make it ideal for the fresh paint to adhere to. An added tweak here is to apply it liberally, especially against the old paint edges. The idea is that it'll sleep in to any potentially loose paint edges, and adhere and seal it down. Wipe away any excess from the top paint surface with a damp cloth, and allow it to dry. Then skim filler, and sand smooth.
Then specialist bathroom paints like the ones mentioned above.
If problems persist - return - you can always consider lining the ceiling with lightweight insulated boards. These can be simply adhered in place, and should end all issues.