What's under my wallpaper?

[_Jonesy_]

I peeled a little test patch of wallpaper in our bedroom today. I was expecting to see lining paper, or the same crumbly grey plaster that pervades the rest of the house, but instead was met with this brown layer. It's rock hard (can't make a dent in it with my nail and makes a hard noise when tapped).

Can anyone shed any light on what it is, and whether I'll need to remove it before painting? I think the wall is blockwork like the rest of my internal walls. It's a 1950s ex council house. Picture below - it's the smooth bit I'm referring to.

Cheers

[tomsugden]

Looks like plaster?

[TGCOTF-dewey]

It's exorcism paper. The catholic church use it to keep evil spirits out.

Looking on my phone so can't see too well, but you should be ok as it doesn't look like you've broken through to the plaster. You'd be screwed if you had.

[wolfracesonic]

Does it feel like a plaster of some sort or some sort of board that’s been fixed to the wall. If it’s a plaster it could be what was called Sirapite b or possibly Keene’s cement, both harder than the gypsum plasters used today. Can you chisel a bit off to see what’s going on?

[ThingsBehindTheSun]

People put wallpaper that thick up for a reason, I think the chances you will just be able to paint those walls once stripped is slim.

[_Jonesy_]

wolfracesonic said:

Does it feel like a plaster of some sort or some sort of board that’s been fixed to the wall. If it’s a plaster it could be what was called Sirapite b or possibly Keene’s cement, both harder than the gypsum plasters used today. Can you chisel a bit off to see what’s going on?

Thanks that’s really helpful, I’ll look into that more.

If it is plaster it’s much harder than any I’ve come across before, and certainly different to the rest of the walls where the plaster is grey and pretty soft / loose.

ETA I think you might be right there, thanks! Found some pictures of Keene’s cement and it looks very similar

Edited by _Jonesy_ on Thursday 13th February 18:48