piece of 3/8 plasterboard , square up the loose plaster , cut the board to fit neatly , dab it to the wall and skim it .
if it's only a temporary bodge to make the house look better i would dot and dab a new bit of plaster board over the whole alcove and just fill the joints and decorate over the board
Chop the old plaster off down to the floor, then dot and dab like art said. Fill any gaps then paint it. The proper job would be to dot and dab then skim. Browning / hardwall is not necessary and too messy these days. (FiL was a plasterer ...)
i think the proper job as Steve well knows would be - lime based scratch and skim it is a nice old house
if you want a quick non messy fix, hack off the lime mortar, then uva the wall to seal in the dust. then screw 3no 18mmx25 battens to the bwk, then get 1 sheet of 8x4 pb, 12mm, measure 3 times, cut once, snug fit, screw to battens fill holes. 1 sheet should fill hole. then paper over it, might have to pop off skirting as said and adjust. I do up old houses for a living, I buy what looks ok, take off the wallpaper, and usually half the wall comes with it . taught myself to render and skim. just finished a house, skimmed it all I did, 'cept the ceilings, I tapes and joints 'em I does.
i had an area like yours around my fire place, i just pva'd it then used a bag of thistle hardwall and spent time smoothing it and blending in. Looks alright, im sure someone with you bodywork skills could do a neat enough job. Once all the walls are painted over it will look fine. How much is that lot £35 quid tops including buying a plasters trowel.
In an alcove, I would board over the whole lot, maybe a couple of battens where the plaster has come off, or just take the rest off and dot and dab. Just fill locally and paper over. A few built in shelves in the alcove would conceal the bodge completely.
I was thinking shelves would help. I'd like to leave the skirting board, it's old and if it gets mucked with it'll split and there's another job. It would also alert a surveyor to recent work and he might realise half the plaster on the room would fall off if you knocked it. The other rooms upstairs have all been completely stripped to the bricks including the lathe ceilings and redone from scratch. This one got left behind as I spent 8 years trying to talk the hoarder ex into empying a huge built in wardrobe. Obviously if I'd known how things would end up I'd have done it myself and burnt the lot.
i would strip the wall all the way down and stick some plaster board on with some [lasreboard adhesive. about 20 quid. as its in a alcove you might get away with papering it with lining paper and paint it... i had to do a whole wall in my house when the ex left ripping out the fitted wardrobe, i got some one to skim it, for 80 quid but that was a whole wall.
