Plasterboard over Straw wall

[dave18uk]

Hey peeps, Redecorating the bathroom which is a mix match of stuff, The building was built in 1875-1880 End terrace. It appears that the original internal walls and ceilings were made of straw and then plastered over. The room which is now the bathroom was originally the back bedroom. When they changed it to a bedroom some time between 1950 and 1980 the appeared to have thrown a layer of concrete / cement over the walls upto about wasit hight. This included making two false walls with the lower half having the area between the stud work filled with 4" - 5" breeze block and then cememt / concrete put over that to about 1" thick then covered in a cardboard material.

Some of the original internal walls are going a bit to the point you can push them in a bit and they are starting to sound very hollow.

Do not want to rip out all the old internal wall as know it will be the most mess ever known to man so was wondering can we locate the wooden frame and then fit WBP plasterboard over the top? This will then end up being covered in either Nuance panels or Tiles depending on where in the bathroom it is. The walls appear mainly level so dont think that would be an issue and dont think it would be too much hassle to the plumber / sparky when they chase for the wiring and pipes

So whats your thoughts??
Also whats the correct name for this style of wall as I know its not Lath and Plaster.

 

[stevethespreader]

Google wattle and daub see if that looks like what you have

 

[dave18uk]

Its kind of like that but instead of say branches this is 1/8" thick straw or reed. Havent pulled enough down to see what its like over a distance only a couple bits the side of a fist. The ceiling is done the same!