Help/Advise Stud wall

[baileyswalk]

I knocked out the doorway and surrounding wall in a cupboard that is being converted into a shower room. I was planning on butting a stud wall up against the remaining wall to close off the room.

However, what I thought would be a single skin brick wall wasn't. It was this really thin mono-block type stuff that looks like it's been made of compressed charcoal or something similar?? It's really brittle and I'm not sure if extending it with a stud wall is a good idea or not (string enough, would the plaster crack at the join etc.?). The other option would be to knock the remaining L shaped wall out and just re-do the lot with a stud wall - but this is a bigger job.

 

[theprinceofdarkness]

I guess the edge you are looking at was supported by a right angle bit of wall. You do not say how thick this wall is. I think that the problem will be fixing your first stud to the wall when its on its foot and ceiling plate. Anther problem will be the different "springynesss" of the two sections of the wall. if they are deflected by some one leaning on the shower wall, then if the joint between the two sections is "sharp" then one will bend more then the other , stressing the plaster and causing a crack. If the transition was gradual, the different movement would be spread over a wider area , so stressing the plaster less. One way could be to drill through the wood and into the end of the breeze block, say 8" and glue in long stainless steel studding with some of the specialised glues for this purpose. Another way could be to drill and plug a big overlap of plaster board along with dot and dab cement.
Knocking the wall down might still give a problem if your breeze block wall was interlocked with another internal breeze block wall. This again would give an unstable edge to fix your first stud to.
Just thought you could try strapping your first stud to the old wall with 3 mm thick punched steel restraints, say both sides and overlapping the old wall by 6" +, depends on the various thicknesses.
Frank

 

[baileyswalk]

Thanks. The original wall is 750mm (including plaster) so I think I could dot-n-dab over the join on both sides after scoring the existing plaster and then secure as normal to the studs - this should strengthen the join sufficiently.

Getting the first stud attached; I was thinking about drilling and glueing in some bolts so that the thread is poking out the existing wall and then bolting the stud to it, sound reasonable?