I've read the advice about rectifying plaster coming off when you paint onto newly plastered walls but is there a remedy or disguise for when painting over previously painted walls where in little patches the old paint flakes off onto the roller?

I did check over the walls prior to painting noticed some areas of loose plaster and took those back, sanded down and felt for other areas that didn't seem sound and it all seemed ok. I really didn't want to have the whole wall replastered if at all possible.

I used to be able to go to my dad for help with my diy but he passed away so any helpful advice will be really welcome.

An addendum to my topic. Have just been to check how the paint was drying and noticed an area close to one of the small patches had lifted off the wall - exposing a larger area and what possibly is an old repair to the wall so am guessing that maybe this has something to do with problem.

Sorry to hear about your dad ellej.

From what you describe, this sounds very likely to be old emulsion coming off from the water (contained in the emulsion) absorbing into new plaster. Once this has happened, the emulsion on the wall has a poor grip, and will show signs of cracking/crazing. A roller is one of the best things to pull flaking paint off unfortunately.

The good news is that you shouldn't need to re-plaster. What I'd recommend is this.

Scrape off as much loose/flaking paint as you can with one of these. I'd also wear some kind of eye protection while doing this, as a flake of dried paint in the eye will spoil your day.

Next. you need to seal the bare plaster exposed after the scraping. You need to do this using contract (non-vinyl) emulsion diluted with 20% water. Once dry, it will prevent excessive moisture from the subsequent coats of emulsion sinking in. This is a 'mist-coat'. Top coats are best done with a quality vinyl emulsion. The contract emulsion is just for the mist coat.

You can use more specialised sealers such as Zinsser Gardz for this type of situation, but this is overkill in most cases. Also if there are any cracks to fill, do this once the mist-coat has dried. It will prevent the water in the filler absorbing, and make the filler more effective.

Feel free to ask more questions on here. There are a stack of friendly pros that will be only to happy to help.

and condolences.

Dyna is spot on and I would say his is the best option for a DIYer. The main thing also is to take your time, do not try to rush the next coat untill the previous coat has fully dried.

Just logged on again to find the very helpful replies to my distress signal. I did know about a mist coat, although I've never had occasion to use it. Thanks for the link to the website. All the suppliers seem to have large tins (maybe more than I need) - would normal vinyl matt not work properly? One other problem on the wall is some patching up has created uneven wall thickness I did sand one area down with an electric sander and that worked well, but read afterwards on one of the forums that that wasn't the best thing to do. I'm not looking for perfectly flat walls as I like a bit of character, is it best to chip away at the excess do you think?

Thanks in advance.

Vinyl matt can be used at a push, but I'd thin it down a bit more than 20% for mist coating. If you have a decorator centre anywhere near you, pop in and they will keep you right, but if you can get contract matt, I'd still recommend using it.

Nothing wrong with using an electric sander for this kind of job BTW. If you're needing to chip away bits of the wall, it must be pretty rough. Keep at it with the sander and flush any higher bits with Easyfill. Some photos of may help here.