chasing socket in cavity wall bricks

jdpl28

Hi,

I'm installing a socket in a wall that's made of cavity bricks. I was chisseling out a section for the back box but went right into the cavity. Now I have nowhere to mount the back box in. What should I do? Fill the cavity with sand/cement?

thanks,
J

DO0GLE

Mount timber batons to the cavity, screw the socket to the timber

jdpl28

Inside the cavity? I need to still have the socket recessed into the wall, so can't see how this would work for that.

GreeBo

I guess he means mount timber to the other side of the cavity
Depending on the size of the hole you made can you not use hollow wall/plasterboard boxes?
The just tighten onto the plasterboard...

jdpl28

don't think I'll be able to do that. It's cavity bricks, so the actual cavity is quite small. And can't get to the other side. And couldn't use platerboard boxes cause the hole is half on the concrete edge and half on the cavity.

cast_iron

I don't really understand what you are saying there, but could you drill into the surrounding blocks (left and right of the hole)?
One screw each side should suffice.
You would have to drill in the middle of the block in case it would shatter.

2 stroke

I presume you mean cavity blocks, these aren't designed to be chased. From here on you will have to make up the rules yourself.

Copper

Hate when that happens. The easiest thing to do is to fill the chase with bonding compound and set the box in it.

Reyman

Are these 9" hollow blocks?

Avns1s

Copper wrote:

Hate when that happens. The easiest thing to do is to fill the chase with bonding compound and set the box in it.

100% agree. No other easy and relatively quick way that I know of.

davelerave

don't use bonding it rots the metal boxes use sand and cement

johnnyrotten

davelerave wrote:

don't use bonding it rots the metal boxes use sand and cement

Since when does bonding rot metal boxes.?

davelerave

as long as i can remember.it would be common knowledge among plasterers and sparkies(me).the same way cavity wall insulation and pvc insulation shouldn't come into contact.one box wouldn't matter that much though

johnnyrotten

davelerave wrote:

don't use bonding it rots the metal boxes use sand and cement

Never happened to me. Strange

davelerave

it takes a few years.i thinks its the urea in the bonding. anyhow they go like a rust bucket after a while

jdpl28

so how should I fill the gaps around the metal box? will plaster rot them too? or just bonding? And arn't the metal boxes galvanised?

fatchance

jdpl28 wrote:

so how should I fill the gaps around the metal box? will plaster rot them too? or just bonding? And arn't the metal boxes galvanised?

They are, I'm a little confused here. I chased an old house recently and half the wall fell in. The whole house was build with 4" cavily blocks in the 50's. The sparkie set all the boxes in bonding, said it was the only way around it.

As for rotting the back boxes......reckon that'd take a lifetime if at all!

davelerave

jdpl28 wrote:

so how should I fill the gaps around the metal box? will plaster rot them too? or just bonding? And arn't the metal boxes galvanised?

just use sand and cement