Mold in one corner

[bengasman]

Very persistent mold, mostly in the corner of the side and rear wall in a bathroom extension and above the skirting on one short wall. Few small splotches here and there, too.
I've inspected the flat roof very carefully and it looks in good nick without any damage or wear anywhere. The facias under the flat roof are in mint condition, perfectly painted and undamaged anywhere.
The outside wall is undamaged and paint is in fair condition.
All and all there is nothing to indicate the problem is caused by water coming in from the outside.

It is a single walled extension with little or no insulation so I'm pretty sure it's just condensation at the coldest points. It's currently painted with what I expect to be diy-shed emulsion, so my first step now is to put proper quality bathroom paint on the walls.
Q1: recommendation needed for 1 or 2 brands for bathroom (mold proof) emulsion.
Q2: do I really need to remove all the crappy paint or is there a primer that will provide enough bonding?

Thanks in advance,

B

 

[blightymam]

From my experience no paint will really work against this, mold will eventually win. Have you thought of an extractor fan or something to help get the damp out of the bathroom?

And yes, it's advisable to remove all the mold before you paint. Bleach will help with that.

 

[bengasman]

Thanks Blighty.
There is an extraction fan already. I'm looking at getting a better one and possibly one that's humidity triggered rather than one that runs of the lighting.

I should have explained myself more clearly.
I know the mold will keep coming back as long as the damp problem itself is not sorted. What I'm looking for is a paint where the mold can be cleaned off, something that acts more like 'woodpaint' than emulsion i.e. fully sealing.

As for removing paint: I can kill the mold with bleach or peroxide and than scrub it off, that's no problem. I was wondering if I had to remove all of the crappy paint or that 'proper' emulsion will take as long as I scrub it with sugarsoap or similar.

 

[blightymam]

Am no expert at all, but I wouldn't have thought you needed to remove the paint, as long as it's sound and mold free. If the spores are dead & mold scrubbed off then they shouldn't regrow under any paint coats you put on.

If it helps, Zinsser perma white get's good reviews, but it's expensive. Might just do the trick for you for a few years going by reviews? Says it's self-priming so should help there too. Never used it myself but have other zinsser products and I rate them highly. Good luck with it all

 

[Grenage]

+1 permawhite.

Well worth the money.