Installing boxes (and cabling) in Bellrock Plaster walls

[rsmck]

Anyone had any experience with Bellrock Plaster Partitions ? Seemed to be popular with John Lawrence (Glasgow) builders in the mid-late 1950s but I can't find may other examples of them.

The entire wall is constructed from a sort of plaster honeycomb (approx 6" wide hexagons made of solid plaster with thin fibre-glass like strands through them) and is load bearing (image attached)

How would you go about mounting back boxes in this - trying to fix a timber batten in the back of the hexagonal section and screwing the boxes to that and plastering them in afterwards seems like the best I can come up with... also the walls sit on timber bases on top of the floorboards, so can be drilled through at the base to bring cables up from the basement below, the upper level is a bit trickier..

The other option we've considered is cutting larger holes out of it, patching it with a small section of normal plasterboard and using simple plasterboard boxes (with flanges) but that seems like a lot of work for a few sockets.

Anyway there must be someone else who's had the misfortune to work with this stuff - any advice ?

 

[imago]

That's used in some of the (ex) council houses in Redditch. The properties with it in that I have worked in have either surface mount boxes with board fixings, or board boxes let in to the honeycomb, or a mixture of the two.

It's awful stuff to work on, but on the plus side running the conduit or oval through it is easy.

 

[Sjn electrical]

Hi,
My nan has it in her house, all i did was put two small batterns either side of my cut out and screwed through the sides ok my metal box.
Looks like i got lucky for once!!
Hope this helps
Steven

 

[rsmck]

That's used in some of the (ex) council houses in Redditch.

Interesting to know it is used further afield, I thought it was pretty much limited to John Lawrence's properties in Glasgow ... in some ways it seems a really good material to *build* with but any retrofitting afterwards is a pain.

I know the more modern equivalent with a cardboard lattice between two bits of plasterboard is quite common but at least that can just be treated as a normal plasterboard wall (and cut out the card in the middle )

Making these boxes look neat is proving tricky though.

 

[rocker]

If it's non standard load bearing I'd be worried about altering the structural characteristics of the building chopping it out. May be wrong but personally I'd prefer to err on the side of caution with this stuff.....

 

[rsmck]

If it's non standard load bearing I'd be worried about altering the structural characteristics of the building chopping it out. May be wrong but personally I'd prefer to err on the side of caution with this stuff.....

It's "partially supporting" the joists in the upper floor (they sit on top of the wall) which span the full width of the house according to a family member who's a surveyor - nothing to worry about removing holes for sockets etc apparently but the wall that we're removing will need a lintel (albeit simply two pieces of timber spiked together, not an RSJ as a brick wall would)

(n.b. I'm not a professional - if anyone is reading this because they've got a similar wall in their house don't go knocking huge holes out of it without getting it checked first )