Help please - bubbling paint problem :-(

9 Sep 2007
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United Kingdom
Hi all,

A few months ago I re-decorated my bedroom. The walls around the windows had some mould as it’s a room that suffers from high moisture levels,. However, I (thought) I made sure I got rid of the mould before re-painting.

Recently, to my horror, I noticed that the paint around the window had started bubbling up and certain areas felt a bit sticky to the touch. I’m guessing the bubbling is due to me not properly preparing the walls, and the stickiness due to not dealing with the moisture levels (though I now have a dehumidifier and air the room each day).

I really want to make sure I deal with this problem properly as I don't want to have to go back to it again - that'd be too depressing! So my plan is to strip off all the paint off around the affected areas and then paint on some damp-block, followed by a layer of stain block. Then, when that's dry, go ahead and re-paint....

Does this seem like an appropriate plan? What damp / stain blockers would you recommend, or are they all much the same?

Any help/advice would be greatly received!

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Scrape the loose paint off, clean the area with a mild bleach solution, rinse and allow to dry. Fill any blemishes and sand smooth.
Apply a coat or two of and then finish with your topcoat.

This, will not stop penetrating damp so if that is the problem then you will need to stop it at source before using it. The same goes for other damp seal paints which may claim to stop it, but in my experience never do.
Thanks for your reply.

I'd be surprised if the problem is penertrating damp due the the proximity of the bubbling, and also the front of the house is very thick brick and has been rendered - i just can't see where any moisture would be able to get in. That said, I'm not a builder so can't be 100% sure.

So I'm going ahead with your suggestion and see if that does the trick. Just a couple questions...

- you say to use a mild bleach solution..i have some mould & mildew spray which contains bleach, would that be ok?

- what filler do you recommend that can be spead very thinly over an area of, say, 10 square inches, and then sanded down so it blends in with the rest of the wall? Is there anything better than pollyfiller?

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Your spray should do the job nicely but probably best to rinse afterwards because some chemicals can affect the paint.
Polyfilla is fine but you may want to use the fine surface version if it needs to be thin. I wouldn't recommend their OneFill for areas prone to condensation.
I always use the all purpose trade version which can be spread quite thinly.
It is also avilable at B&Q
Also, I can't quite remember if the Zinsser I recommended should be colour tinted rather than painted over. Best to check before you buy or go for a different brand anti-condesation paint.

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