Plastering an old house

I've just removed the woodchip from my new 1930s home to discover a thin layer of yellow paint or primer which has fallen off in places to reveal a grey plaster like substance which is about 5mm thick. In places there seems to be a little bit of give between the two layers so it seems like there's air trapped between them.

My plan was to plaster the deep holes with ready-mixed plaster and allow it to dry before sanding it down and painting the wall with primer, then sanding back to get a fine smooth surface then reapplying the base-coat if necessary before painting as normal. Does this sound OK and have you got any advice on what primer I should use?

Responses from some of our very best tradespeople:

"Remove any loose or suspect plaster from your wall, mix up a Unibond solution with water 50/50 ratio, apply this to the wall -if the depth of holes is greater than 4-5mm then apply a tight coat of Hardwall base coat first. Then give the whole wall another coat of Unibond-water solution-30/70 ratio. If Hardwall has been used then use a scrim tape around the edges of the Hardwall areas to prevent any cracking. Then set the wall as normal i.e. 2 coats of multi-finish, the first coat may dry pretty quick but the second coat should cover this and give you enough time to get across the wall."

Mark Pratt, MP Plastering
Mark started out in 1992 and has worked on many types of buildings from commercial to domestic both large and small. Amongst other services he does: re-skimming, floating and setting, rendering, tacking, dry-lining, screeding, coving, ceiling-rose fitting, partitioning and stud work. Mark works in and around the Bournemouth area.

"Sounds like a big job, so if you don't want to go down the whole re-skim route, then your method sounds fine. Anything that is loose needs to come off, or the screws might come away. I would use a PVA glue (watered down) can vary between 5/1 or 3/1 in ratio as a primer, then fill and sand away, if that fails you'll need to re-plaster."

Michael Ball, Wallplas
Wallplas are a reliable company based in the Greater Manchester area. They offer a wide range of plastering skills; from patchwork, dry-lining, skimming, and re-skims to a full rip out of a property and rendering. Recently they've added a Venetian marble plaster to their offering. Wallplas will do any plastering job and take on sub-contract work as well. They take a lot of pride in their work and ensure a clean and tidy service to all their customers working in the North West region.