3 Inch Breeze block walls

[Chit]

Hi guys, a client of mine has told me about some of the internal walls in his house. He has a mid 1930's semi and says that the 1st floor internal walls are made from breeze blocks which are no more than 3" in depth.

I know the ones which he is talking about as I've seen these in my old house myself. He was trying to gouge out spaces in this wall to fit patress boxes but apparently he managed to cut right through the wall as the breeze blocks are quick weak and crumbly.

Just wondering if any electricians on this forum have had any similar problems?

My advice was that I'd weld a strip of metal to the back of the patress boxes, slightly proud of the edges of the patresses, (firstly they'd all be in a straight line and look nice). Secondly, he could then fit these from the other side of the same wall, gouging smaller pieces of wall out in which to fit the slightly proud strip of metal, and then fill in or build up the wall from the front and back with bricks and cement....

He fitted them in this way and from the pics, they looked fine, after the decorating, you couldn't tell what had been done and so he was pleased.

Just wondering how electricians deal with these thin breeze block walls? Is there a trick that you guys use?

 

[sparkiemike]

I presume the wall is going to be finished in plaster board or plaster. In this case I would simply fix 25mm boxes (and cable) on the surface of the bare wall. When the plaster or boading is complete then the boxes will be burried. No need to make holes in the breeze block

 

[ban-all-sheds]

How did he get on welding onto galvanised steel?

 

[Chit]

How did he get on welding onto galvanised steel?

Spot welded the patress boxes on to the metal strip running behind them....?

 

[Alarm]

How did he get on welding onto galvanised steel?

Cleaning off the galv, and very low amp setting

 

[smars]

You can chop a box out into 3 inch breeze wall without breaking through the other side. You have to be very careful though. It is best to 'pepper' the area you are removing with a drill. That way you don't have to hit the wall too much.

 

[davelx]

You can chop a box out into 3 inch breeze wall without breaking through the other side. You have to be very careful though. It is best to 'pepper' the area you are removing with a drill. That way you don't have to hit the wall too much.

Been there, wish I'd done that. Chopping out for a shaver socket (deep box) in the wall between bathroom and upstairs landing. Cold chisel went straight through the wall and down the stairs.

I grip-filled the box in, made good the hole behind it with cement and plaster, popped a couple of screws in for good measure. Then I just had to re-decorate the landing side of the wall.

 

[Taylortwocities]

Done that in recent cottage refurb. This had a thin (3 inchish) internal wall made of cinder block to form a cavity from the original (damp) wall/

Solution:


Use mighty strong cement and glue the box in to the hole.

Fit plasterboard flanges as wings on the back box first and the cement and subsequent plaster will hold it, no problem.

 

[ColJack]

sink it 10mm and overboard the wall.. gives you about 25-35mm..

one of the guys I used to work with once put a 45mm deep box into a regular block wall and managed to push the tiles off the back of the wall with the screws..

those walls are unlikely to be load bearing so my advice would be to remove any that are crumbling and put up stud walls.. by the time you've made good and platered / overboarded them you're halfway there anyway..