Patchy plaster after stripping wallpaper

[duotwr]

Hi

I've just been stripping the wallpaper from our living room. On one wall lots of plaster came away with the wallpaper - what I imagine (from my position of ignorance) to be the last skim that was done prior to wallpapering. It's only come away to a depth of about 2mm at its deepest with solid plaster underneath. I'd say approximate 50% of the wall has lost plaster and the rest seems fairly sound.

I'm planning to line and paint - and (what a surprise) don't immediately have the funds for a plasterer. Is there anything I can do - am up for trying to sort it myself - accepting how difficult plastering is - but I'm not sure what type of plaster to use, and how.

Any advice would be gratefully received!

Keith

 

[JohnD]

I am not a plasterer. I usually do repairs and patches using fine finish plaster, with a broad springy metal filling knife or a plasterer's trowel. I have tried patching plaster but I find it sticky and does not leave a fine surface. Fillers are usually harder to use and smooth, except on very small blemishes.

Clean off all loose bits and dust. After brushing dry, I like to use water and a brush to get remaing grit out of holes. You can then treat with PVA adhesive in water to improve adhesion if you want. You have to clean any remaining PVA off the surface as it softens with paint or paste.

Make the plaster mix fairly soft so that you can press the metal blade onto it, bridging across the existing plaster at both sides. When it has firmed, spray or flick water on it and polish smooth with your trowel; held flat.

If it protrudes at all proud of the rest of the wall, scrape it flat with a broad rigid metal scraper before it is fully hard, them spray and smooth again.

Scraping new plaster of filler is far easier and cleaner than trying to sand it smooth, which many amateurs try.

Real plaster sets fast, so mix small amounts in a tub, and clean the tub and tools very thoroughly before each mix.

I have also heard good reports of the plaster used for filling taped joints in plasterboard, but have not used it myself for patching.

Clean all traces of wallpaper paste off the wall before you try to redecorate. Warm water and a broad scraper will take it off as soft sludge which you wipe off the blade.

I like to give the wall a couple of coats of matt white emulsion after I have patched it, this levels out the colour and makes it easier to see any remaining blemishes that you need to deal with. IMO a painted wall is also easier to clean and paper, but opinions differ on this. It is probably time and effort than a professional would want to avoid.

 

[Richard C]

Sounds like the re-skim has come away; this could be due to lack of or incorrect preparation before it was skimmed but did you, by any chance, use a steamer for stripping the old paper off? They are very good at stripping paper but if you leave them in one place too long, the plaster skim will overheat & it pops off the wall, you can actually hear it happening when it does.

To attempt DIY skimming with finishing plaster without any practice is not a good idea TBH, too many things to go wrong & if you’ve never plastered before, the results are likely to be rather disappointing. Finish plaster goes off very quiclky & is not designed to be sanded once it’s been put up, you’d be better off using something like Easyfill (the product JohnD refers to) which can easily be sanded to get a better finish. It’s going to be time consuming, very dusty & won’t look as good as a re-skim but it may look good enough to get you out of a hole until you can afford one.

If you still fancy having a go at skimming a look through the Plastering Forum archive posts will give you plenty to think about, lots of background info & pointers.

 

[JohnD]

ah, the re-skim coming away, I hadn't registered that - I was thinking of cracks and patches.

yep, save up for a pro plasterer. A few hundred pounds should do it. But get all the loose stuff off.

 

[duotwr]

Thank you for the replies!

I'd seen the comment about flamboyant steamer use leading to the skim coming away in another thread - but not in this case, I was only on the warm water and sponge method

Sounds as if this might be a job too far - to be honest the section of wall is below a picture rail, and so is only about 2m x 3.5m - so assuming I can get a plasterer for such a wee job it probably won't be too expensive.

Thanks for the advice though. This is a great site - and having recently moved into a new house I'm finding myself on here more and more.

Keith