Zinsser Perma White Mould Paint blistering off the walls

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So we had a whopping wet patch on our bedroom wall. The leak was identified as being an old one thankfully.

I was told to hit it with Fungicidal Spray, which i did...
http://www.decoratingwarehouse.co.u...leaning-products/mangers-fungicidal-spray/229

I was told to get some stain block on it, which i did...
http://www.diy.com/search/stain block/Ronseal-Stain-Block-Aerosol-White-400ml-9253602 (although looking at the reviews, maybe that was a mistake)

& then hit it with anti mould paint, which i did...
http://www.decoratingwarehouse.co.u...e-coatings/zinsser-perma---white-eggshell/586

Self priming it says.

Anyway 2 months on it started blistering.




I scrape it off, come back a day or so later & even more has blistered.

It's a nightmare to try & scrape it off. I tried light sanding it but that didn't help either.


Yes it was a clean surface when i started.

Why is it blistering & what should i do now?

What i'm bothered about is getting wallpaper on there & then it continues to blister & then lift the paper where it's blistering.

The tin says self priming but then i noticed it also says this about Bullseye primer...


So does it need primer or doesn't it? And if it's needing primer, is this stuff going to be ok to paint straight over what's already on or am i somehow going to have to get that off?

Thanks.
 
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The bits that are flaking look darker to me which suggests that you still have a leak and hydraulic pressure is behind the flaking.
 
Is there another likely reason? I ask because I didn't rush in painting that stuff on. I stripped the paper & the wall was darker in that patch. I left it 2 month & in that 2 month it hammered it down at times ... But the wall still dried out/lightened to match the rest.

Suggestion of removing that paint without gouging the walls?
 
If the wall is still drying out then you'll trap the moisture in and cause bubbling. Just scrape it off, it won't take 5 minutes to patch later.
 
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Maybe I didn't leave it long enough then, but it was 2months with a dehumidifier in there too.
I emailed Zinsser who gave 3 possible causes, including the damp wall you mentioned.
The 2nd was older paint layers poorly adhering to the plaster. This can't be it as there was no paint on there, so there are no 'old' layers.
The 3rd was the plaster being very powdery. I don't know about this but I suspect it is the original 1930s plaster & it's quite dusty.

They recommended their "Allcoat Solvent Based" to be used instead as they say it's breathable.

They say I don't need to scrape all the paint off the wall, but surely if the Perma White is not breathable (& therefore suffocating the wall) then surely i'd have to?!
 
Went to the house tonight & started scraping. I took a bit much off & created a hole in the plaster.

Anyway, the photo seems poor (the one you commented on) as the plaster (to me) looks the same colour as the dry stuff. At least on the surface anyway. It doesn't look darker. Once i'd created a hole fair enough it did.

Anyway it's very gritty (the plaster).



Close up of the bit where i'd scraped too hard...


Do any of you know how this would react to wallpaper going over it?

Reason i ask is my concern is if the paint is flaking/bubbling/blistering then if paper goes on & the paint continues to blister, it'll (in my mind) lift the paper away from the wall. Would you expect this to happen?
 
I've just taken a look at that product they recommended. £65 for 5ltr when it may not even work. Forget that for a carry on!!!
 
Dry scrape all the loose paint and plaster off and brush away all the dust then make sure the surface is completely dry before applying a coat of alkali resisting primer to the bare areas. Do not introduce any form of moisture to the wall until you have applied this, not even filler. Allow the primer to dry completely, then you can fill the surface defects. If you need to sand the filler, ensure you do not sand through the primer. Prime the filler and allow to dry thoroughly before using your chosen finish paint. Hopefully this will work and is a lot cheaper than trying the Zinsser Allcoat, but it's not guaranteed.
Of course, if there is still moisture penetrating the wall from somewhere then nothing will work until the source of it is remedied.
 
Follow Misterhelpfuls advice but also I'd recommend that after applying the alkali resisting primer, apply two coats of Ratcliffe's Glutenglass as an insurance, thereafter you can paint the walls with an emulsion of your choice.
 
Thanks guys.

No not vinyl, just paper. I think it's that paste the wall stuff or at least the feature wall is.

Really though, I'm wondering if I'm creating work - how much of this attention is actually NEEDED if I'm going to paper the wall?
If the paper will take to the wall ok then I guess the answer would be to stop making work & get on with it. If the paper is likely to flop off then I suppose it's needed.

I know I'm guilty of over thinking & wanting everything perfect & by that I can end up needlessly creating work. I did that with a paint job in another room. I just wonder if I'm doing the same with this wall & it'd be good to maybe not paint over, but paper over, which is what we'd be doing.
 
You can just fill, sand and paper if you want to, but by your own admission, the bubbles reappear a day or so later and for them to appear so quickly really does suggest that there is moisture within the wall. This means they will continue to do so with paper on top and, while it is highly unlikely to make the paper fall off the wall, you will still get the blisters beneath the paper which are likely to protrude through the surface and also loosen it to a certain degree.
If you are using a paper with a busy pattern then it is less likely to notice, but will feel 'crunchy' when you touch it and possibly stain through it. As mentioned previously, our suggestions are not guaranteed, and some surfaces will always be problematic, but if the issue isn't addressed to start with then you will never know if it would have worked.

*Edited for my poor English! :eek: :LOL:
 
Thanks.

I had a dehumidifier stuck in there & it was drawing out but it stopped taking much out towards the end of me using it in that room.

The surface of the plaster looks very dry. When i gouged that bit out it looks darker behind, perhaps wet, but obviously unless i chip away i can't see it & we're not going through the re-plastering process again after the episode with the living room.

Oh & i think i may have given the wrong impression - the paint had small blisters, which i'd then scrape off. Leave it a few days & the edges of these scrapings would then be lifting slightly & would scrape off quite easily.
 
Zinsser responded saying their £60+ tin is the only thing they do that's for the job.
Be that as it may, I'm not paying it.

Is there any way, aside from hours of scraping, that I can remove the paint currently on there? Can I coat it with some solution for example that would help remove the paint from the walls?
Or is scraping the only answer?
 
Why are you looking to remove all the paint if you intend to wallpaper?

It's the plaster/substrate that is causing the issue, not the paint, and if you don't intend to use any of the products that have been suggested then I don't understand why you want to remove the paint. Or are you going to use an alkali resistant primer/Glutenglass and I have just misunderstood you? :confused:
 

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