Sealing plaster - HELP!

[clive242]

Hi,

My en-suite has suffered from mold/condensation damage (above our small window) over the years so I decided to re-paint the en-suite with a good quality bathroom paint (Perma-White Mold & Mildew proof self priming paint (interior white eggshell)). My problems have just started. I have removed all paint in the affected area and then I treated the affected plaster with a fungicidal treatment, of which I put on two coats, 24 hrs between each coat, I then left the final coat to dry. I have since applied my bathroom paint to the whole bathroom, however where we had the mold/mildew damage above the window, the paint has started to flake? I have had to remove all new paint again and then re-applied the bathroom paint again to the affected area, but today I have noticed the paintwork has started to flake again?? Is there sealer out there that I can apply to the plaster and then paint over it once it is dry? I am at my wits end and don't the way forward, any help out there would be much appreciated,

Clive

 

[misterhelpful]

Couple of questions:-

1. Did you rinse the area after applying the fungicidal wash, as this is usually necessary?

2. Is the area concerned completely dry when you paint it as most paints will not adhere to damp surfaces?

If the wall is damp then you could use a damp seal paint (some are suitable to apply to damp surfaces) to try and solve the problem but ideally you need to solve the condensation issue.

Do you have an extractor fan to remove excess steam? If not, then this is likely to be the source of your problem.

 

[Richard C]

You are suffering an adhesion problem. If you removed all the paint from the plaster in the affected area the plaster will be highly absorbent & if not primed with either a wash coat (matt emulsion thinned 25-30%) or proprietary plaster primer, it will suck the moisture from any paint you apply before it has a chance to stick. I’ve no idea the properties & have never used any sort of anti-fungal treatment to kill mould (I find a white Vinegar solution works just as well) but did you check if it’s suitable for use on bare plaster? Do not be tempted to use PVA as a primer, which will only make matters worse. Of course if it's still damp, the paint won't stick anyway