How to fix flaking paint on plaster wall?

[maro]

 

 

 

hi everyone I was wondering if someone could help. I have a little problem as I’ve been preparing the walls for painting. I checked online and it said that I should flake away loose bits of paint but as I do that more and more keeps coming off. I can’t do the whole flat. It’s impossible. Does anyone have any solutions for me please? I’m worried that painting over this will not allow the new paint to stick properly. is there a special primer that I can use that will go through the old paint and make it more secure to the wall? Any solutions please would be welcome. Thank you. I’m attaching photos! 

i found this  zinsser peel stop - will that work? Can I paint over that’s after it’s dried? Also what can I do about the unevenness between where the paint has flaked off and where there is still old paint? Thw plasterer is coming on Wednesday to white set plaster that rendered square - should he whiteset the areas where I’ve removed paint too? And then I send back before priming? Or sand first, then zinsser and then white plaster?  And should I apply the zinsser all over all the walls?  I’ve seen nightmares scenarios where paint just completely peels off because of poor Prep. Help! Thank you!

[EricL]

Hello @maro 

Looking at the cracks on your wall it appears that the plaster has been compromised and that your plasterer will have to plaster over the cracked areas. This is of course on the condition that the plaster is not falling off and is still very well attached to your wall. In regards to the paint, if you get to parts that are difficult to peel and still attached very well to the wall, then you should stop there. 

I understand your worry that you might end up repainting the whole flat. But I recommend removing only those sections that are curling, peeling and detaching from the wall. You can leave the flat solid sections alone. 

Once the plastering begins make sure to remind the plasterer to do all those cracks and to level it with the existing paint surface. When the plastering is done, I suggest using Zinsser Peel Stop Binding Primer Clear 1L as the primer for that wall. Since it is water-based you can use any water-based top coat paint you prefer.

If you need further assistance, please let us know.

Eric

[maro]

Thanks very much Eric 

so the zinsser peel stop goes on after the white plaster? Or do I have to put it in the edges of the flaked paint before the white plaster goes on? In this video I watched, the painter scrapes off the flaky paints, sands it back, then applies the zinsser, then he fills the gaps where there is  missing paint with filler (his wall is plasterboard not render) https://youtu.be/G-BVrjFhqfs 
im confused because there was a bit on another wall that the plasterer had put some white plaster on, and when I tried to sand it smooth , that’s when I realised there was a problem with the old paint - the white plaster got sanded back but the flaky paint was still protruding and there’s still lots of unevenness. Sorry I’m not sure how to explain it. I might need to go back to the flat to take more photos. Maybe he isn’t using good plaster? The plasterer is also very slapdash, just wants to finish quickly and doesn’t appear to want to do a thorough lasting job. Just wants to come , faff about, do as little as possible and then go home. His boss doesn’t keep an eye on What he does so it’s up to me to know and understand what needs doing.  

im so stressed. I’m worried that the whole flat has unstable paint and plaster. The bit you see in the photos just happens to be the bit  where I had to flake it back because of that hole in the wall. But I’m worried that the rest of the Flat also has paint that hasn’t been primed properly and that there are cracks in the plaster behind all the rest of the paint that looks smooth,. What you see in the photos, that all also looked nice and smooth before it all flaked off so easily. It looked flat and smooth and I never would have thought it would all come off as easily as it has. Is there a danger that it all falls off after I try painting it? I mean the paint in all the rooms in the flat? How can I prepare the walls in the rest of the flat to try to prevent a disaster happening? Should I sand them and then use zinsser on them too, or another primer? 
But about sanding, I am also worried there is lead in the paint because it’s a 70 s flat. I had previously tested the paint on the architraves and that came up positive for lead. Is wall painte from 70s also likely to have lead in it? 

[JacobZ]

Hi @maro,

Unfortunately, I am not confident that the Zinsser Peel Stop Primer would be enough if all of the paint is flaking off. This stuff works by gluing down raised edges; it doesn't penetrate through existing paint to help it bind to the surface beneath. Like @EricL said, if you can remove the flaking paint to a point where it stops coming off, then you can stop there and use the Zinsser Peel Stop Primer to glue down the edges, then plaster over it, before priming the new plaster and painting.

The only way you can be 100% confident that your new paint will stick and stay on for as long as it should, is to remove the old flaking paint, touch up any cracks in the plaster and then prime and paint.

Considering there may be lead present, I'd suggest you speak with a professional painter who has experience dealing with lead-based paints for their assistance. Unfortunately, there are a number of variables at play that make this job more complex than a simple touch-up job.

Allow me to tag @Nailbag to see if he has any thoughts or guidance he can offer.

Jacob

[maro]

Thank you very much @JacobZ yes I will try to get a professional painter to help 

i appreciate your advice - Thank you 

[Nailbag]

Hi @maro 

It's difficult to tell exactly from the photos, but the cracked area doesn't look like traditional plasterboard but possibly a fibre cement product thats been rendered over or an internal direct to wall render product. The covering looks too thin for plasterboard and I can't see evidence of a more traditional direct to wall adhesive. Possible causes could be moisture (unlikely as the main wall isn't stained), or the wall itself has moved and cracked. This would cause the flaking paint and render, but if plasterboard/cement sheeting I wouldn't expect to see cracks all the way through.

Regardless of product, unfortunately as with @JacobZ and @EricL my recommendation would be to remove all of the damaged sections around 200mm out further from the damaged area. This would allow you to hopefully establish the potential cause of the cracking and have that rectified before replacing with new. 

And yes 100% agree with your point about the most important part of the restoration is in fact all in the prep.

Please keep us in the loop of progress and what the wall product is.

Nailbag

[maro]

Thank you very muchI @Nailbag 

no it’s not plasterboard, it’s white plaster over sand and cement render, I’m not sure what kind of white plaster. The plasterer had said something about lime-something but I don’t know.

I was wondering what you mean by « traditional direct to wall adhesive » ? 

I did notice as I was scraping away that there were some blue bits in certain parts under the paint. You can kind of see it in the photo around the edges of the flaked paint if you zoom in, Could that be the direct to wall adhesive ? 

[Nailbag]

Hi @maro 

Direct to wall adhesive referred to if there was traditional plasterboard fixed to the wall, which you have clarified as no. So it's the original "lime-based" render thats cracking, but potentially caused by the wall itself cracking causing the render to crack, or simply aging render and paint. Its likely the later due to old products not being anywhere near as flexible as modern ones that your plaster and painter will use. This is a sample of what type of product that the plaster will use as an FYI. But he/she will know the best for your repair.

Nailbag

[maro]

Thank you @Nailbag yes that’s probably it, it’s an old flat (70s) so probably caused by building movement. I hope it’s stable enough and doesn’t need to be completely removed. It does feel solid, don’t look like the plaster is coming off so hopefully will be ok. Thanks again for all your help ❤️