any idea what this is?

[scotsgraeme]

while moving a couple of sockets today i found a wall i expected to be plasterboard, wasn't. instead a skim of plaster, over what looks to me like cement mixed with straw or hay, with a wooden frame behind it.
the house was build in 1960, ex council and this is on an upstairs "extra room" overhanging the footpath outside, with a concrete floor, battens then floorboards

 

[gregers]

its a strammet type construction??,iirc there was a very detailed reply by someone over the last year about this very same question.

 

[scotsgraeme]

thanks, tha'ts exactly what it is. i guess i need to sort the insulation behind these boxes now :/