New DIYer - probably an easy question on plaster....

[moonhog]

Hello (and Merry Christmas)!

I am a new homeowner, and have recently purchased a Victorian terrace (c. 1900) with textured wallpaper/anaglypta on most walls. I have removed the paper in the lounge to find a light greyish wall, which I assume is normal plaster and 'skimmable':

However, I have just removed a small piece from the hallway (it came off easily) and found a gritty, sandy surface that rubs away easily:

Would someone be able to point out the difference? I don't want to remove anymore until I understand what this layer is....

Many thanks in advance.

 

[roy c]

This is common with an old Victorian house. The top coat plaster (nowadays called "Skim") would of been what was called "Keens" cement which was applied on to a sand and lime background which horse hair or ox hair was added to the mix to bind it together, You will find on Partition walls laths of wood which I think were made of willow or similar wood because of the straight grain and were gapped by the thickness of the plasterers finger or the labourers, and the sand/lime /hair mix was spread on it and the muck that went between the laths spread out and held it together , (there must be hundreds if not thousands of houses still with this on their walls) I for one have an old Victorian house and the hall and up the stairs still has this method on the walls a bit rippley but original. I can remember the old siraphite (Not right spelling) the story was that it contained cellulose and a lot of women used to add it to food as a dietery substitute,(not found a woman who agrees with this!!!! ) that was used after Keens cement was phased out and this was like the skim we get today but you had longer to "Play" with it and after you had "devilled" your wall and left it to go off then you put your siraphite on you could bring it back up the next day with a drop of water and a wooden float!!! Then trowel it to a finish.. Don't quote me on any of this but as far as my memory goes this is how I remember things. Some of the old boys might correct me on a few details, but I welcome that...

 

[moonhog]

Thanks for the reply, Roy.

It's almost as if there's a thin layer of paper on the back of the wallpaper (but they pull off together). I thought it might be some kind of plasterboard, and that the wallpaper had been directly stuck on.

Any ideas on how what to do with it after removing the paper? I don't want to remove anymore until I know how to proceed. I guess some sort of stabiliser/PVA would need to be applied to stop it disintegrating.

I don't suppose you know if Keens cement ever contained asbestos??

 

[roy c]

To me it looks like there is a thin skim of plaster under the paper so it may of pulled off when you took the wall paper off. But if that was the case I would of expected the plaster to have "devilling" in it. (Scratches to give the skim coat adhesion). But maybe it is old plasterboard and the skim has pulled the paper off when it was stripped, What you could do is just dig a bit of the plaster off gently and see if there is paper underneath. If it is sound (whatever it is) you can Pva it or sbr it(2 coats and on the second coat skim it when it is "tacky", leave first coat of pva or sbr to dry before applying second coat ).Like I said it might have been floated out flat and not devilled (which would of meant that the skim coat pulled off with the paper) or it might be plasterboard and the paper has pulled off when the wallpaper was stripped,(which you might find out when you scrape a bit of the plaster off and see whether there is paper underneath). In the hallway I should imagine that it was plaster put onto laths and skimmed over so you might find some wooden laths when you gently scrape a bit out. Good Luck...

 

[moonhog]

Cheers Roy. I've stuck a pen in it, and gently dug a bit out. The first 10mm was quite 'sandy', and then some bigger chunks were behind it.

There's also some green/emerald patches that haven't peeled off with the anaglypta paper; these can be see in the photos, and also the remains on the back of the paper when peeling it off. There also seems to be a straight line, perhaps a joint in the plasterboard?

Before I go and 'rip it all off, might there be any benefit in perforating/soaking the anaglypta and trying to leave the green/emerald layer on the plaster? At the moment it comes off easily without any effort.