Any regs (Part A) concerning depth of boxes?

[Smugley]

Hi all, quick question about building regs. I need to install a shaver socket (selv) and as these need a 47mm box, it got me wondering about the thickness of the masonry wall which I haven't measured yet but I guess is about 100 to 120mm. I know the regs regarding max depth of vertical and horizontal chases, but is there a rule about how deep you can go to chop out a back box? 47mm into a 100mm wall is getting close to 50% depth. Would this be a cause for concern? The IEE guide to building regs doesn't mention anything but I haven't looked up Approved Document A in full yet.. Cheers.

 

[acat]

I dont think there is anything. Considering its size compared to the wall itself I doubt it would be a problem an extractor fan would go right through the wall and is bigger??? Thats my logic anyway.


Chris

 

[Smugley]

Cheers, yes that's a good point about the extractor. Just got me thinking about how big a hole can be before it becomes an issue for wall stability.

 

[baldsparkies]

Acro prop each side of the wall and install a 9" RSJ, before chasing.

Just kidding mate its not a problem, the chase out is not going to be big enough for concern, just take it easy as you aproach your final depth.

 

[Mr Mark Sparks]

i agree no issue with depth of box, as said take care near final depth.
if you do chop right through to the otherside just put a picture over the hole

 

[sparks1234]

I think the logic is when you chase, if you are very deep you are considerably weakening the wall from either top or bottom to your box, obviously more than 50% will weaken it