This was a question I received from Mark, a homeowner looking for advice on a sealer prior to wallpapering. It raises a few points, so I have posted it here so it can be of use to others.
I am decorating the small bedroom in my house which was built in 1957. I’ve had to renew quite a lot of areas of plaster (in patches) where the breezeblocks behind had gaps in the mortar (yes it was a council house!).
When it was built they seem to have painted all the plastered walls with some sort of coating, it’s smooth almost like eggshell, and is a light yellowy-buff colour. I was wondering what this was, as I’m keen to keep to ‘traditional’ methods and materials, and will need to cover up all the newly plastered areas before wallpapering.
My local DIY shop recommends a PVA/water mixture coat first, then a coat of size. I’ve looked at products like Halls Primer Sealer, and the similar one from Dulux, but would rather apply what was put on originally if possible.
Thank you for your time.