Advice on preparing walls for painting?

[baps]

Hi folks,

Excuse the newbie question, I'm sure this is pretty straightforward. Have a couple of areas in the house where the old paint is flaking. Problem is if I sand it, the paint continues to flake off until I have a large area of plaster and still flaky paint around the outside. Attached is a pic of one bit that I've sanded a bit and exhibiting this problem.

While there's been damp in a couple of places, it appears to be mostly dry. There's no salt appearing and the walls are dry (or drying in places, but that's another problem). Since I didn't know whether to continue sanding until the whole wall is bare or not, I tried undercoat on one area to see if painting over it would sort of seal it in. Roller pulled the old paint off the wall, so that's not going to work. Probably should have expected that, right?

So, 1) do I just continually sand until the old paint can be feathered out/removed? (this'll take some friggin time!)
2) any suggestions as to what to do with the area I've tried painting? Just sand it all back as well? Included pic of this too in case it helps any.

Probably silly decorating questions, just think it may well take days to sand all that old paint off if that's what needs to happen. So thought it might be an idea to see if there's a better way to deal with this.

Many thanks,

Baps.

 

[Chri5]

Damp has lifted the paint. Has the damp problem been sorted?

It's going to be scraper, steamer, sander, filler, sander, mist coat, two coat. If when sanding the plaster chunks are flying off suggesting the plaster is sick (due to moisture overload and then drying) it will be better to re plaster / skim with some pva to bond old to new.

 

[baps]

That second photo, where you can see the patches I've been trying to sand, there's marks on the wall look like there's been water running down it at some point. Plaster seems bone dry, as is the wall above it, so I'm guessing that was some time ago. Two other spots around the chimney breast and a window have been recently damp and have been drying for a couple of months now, but that patch I attempted to paint I can find no source for damp there. Doesn't mean there wasn't at some point I guess. Don't think the majority of the house has seen any new paint in a long time.

Haven't tried scraper, might be worth a shot. It's like the paint in most places is just marginally detached from the wall. Like that portion in the image was a couple of small spots, but as soon as I sanded those small spots, it continues to flake around them. Sand the new flaky parts, more flaky parts. Rinse and repeat. Also have some polycell smoothwall I've used to patch up some rough plaster elsewhere that's done quite a good job (I think), so perhaps that would work? Is as much a case of removing the flaky paint continually, or try something else I guess. So far, no plaster flying off the walls, so that's a good thing I guess!

Thanks for taking the time to reply. I see a few similar threads here, so hope I'm not repeating what's been asked a thousand times before (which I probably am).

Baps.

 

[blightymam]

Is as much a case of removing the flaky paint continually, or try something else I guess.

Unfortunately once the paint is lifting off, the only thing left to do the job well is to remove all the flaky paint - you've already experienced the roller pulling the paint off, this is what happens sadly! I know it's a pain in the..... but if you do it well, once and for all then you shouldn't ever get a problem again in the future.

You don't need to sand it off - can be a lot of work but as Chris mentioned, a steamer and a scraper will get the paint off quicker. Then just sand down any last bits too stubborn and make the wall uniformly smooth.

Good luck with it all!

 

[baps]

Thanks, appreciate it. Will have to buy more sandpaper!

On a somewhat related note, any thoughts as to getting paint off PVC door frame? I've tried scraping the frame trying to take it off with a scraper or chisel, but I can't seem to do it without damaging the frame. Guy in hardware shop said paint stripper isn't a good idea on PVC as it might burn or damage it. He suggested just painting over the old paint. Not ideal, but if I can't get it off, it will have to do I guess. Is there anything that might safely remove it from PVC?

Baps.