Possibly the worst wall I have ever worked with,

eskimo39 · May 2, 2011

Can anyone here give me some advice? I am currently doing a full rewire on an unoccupied house but having some trouble chopping in backboxes.

All external walls are fine but the internals are a real nightmare. They are made of a kind of soft breeze but have like a large 2" cylindrical hollow running down it every six inches or so. When trying to chop in i just end up breaking through the other side and cannot for the life of me get a flat back to fix to.

Anyone have this before.

Also the customer wants rid of the pull switch in the bathroom so I was going to chop a box in but found out it is a stud. No problem I thought as I would just use a plasterboard backbox but it is Lathe and Plaster. Will a plasterboard backbox work in this? Or am I best removing a section of lathes between 2 studs and replacing with plasterboard?

Cheers

EDIT: Sorry should read worst wall not works wall.

rocker · May 2, 2011

For the lathe walls I normally remove an area of the lathe and plaster larger than the boxes I want to put in, then cut a section of plasterboard to fill the hole. Screw battens into the inside of the lathe wall leaving an overlap, then screw the plasterboatrd into that. A very quick skim, wait for that to go off, then cut with your padsaw and fit dry lining box as normal. It's a bit of a faff but makes for a much stronger fix - I've tried larger boxes to fit straight to the lathe wall, but with pulling plugs in and out, they don't last 10 minutes.

nickblake · May 3, 2011

this type of block are very common round here your lucky you have an unoccupied house , its a pig when youre trying to get the power on , what i do is as has been mentioned use some bonding plaster ,do all your chases ,mix some bond up fill the hole push in and level the back boxes ,then leave till the next day , then drill and plug they are not going any where after that , the plaster would probable hold them but more proffesional if you screw them up to