47mm Electrical backbox - Block Wall

Fawkon · 23-02-2023 3:34pm #1

I’m looking for advice on how I could find a solution the the following problem.

Currently in the process of building a home and was planning to fit a mounted electrical toothbrush charger.

I have asked the electrician to wire as appropriate but have just learned that it is highly discouraged from chasing anything more than 35mm from a concrete wall.

Is there any solution where I can accommodate fitting this charger without having to chase further than 35mm?

it’s location would be on an external block wall just above the Ensuite vanity.

thanks for any guidance or advice!

10-10-20 · 23-02-2023 3:39pm

The wire-chase or the back-box knock-out? Surely it's the wiring chase which is at issue here - it's the linear cut greater than 35mm which could potentially cause a structural fault - BUT you don't need the wire buried that deep, do you? 25mm would suffice, no?

If he's concerned about chasing for the back-box - then how does he think walls stay upright when ventilation holes are installed straight through them?

jumbone · 23-02-2023 4:17pm

dot & dab board the wall, green board or a cement board product for a jacks

Fawkon · 23-02-2023 8:13pm

https://www.boards.ie/discussion/comment/120279733#Comment_120279733

It’s the actual back box knockout I’m concerned about, the depth of the charger in question is 45mm so would require a 47mm cut out.

Fawkon · 23-02-2023 8:17pm

https://www.boards.ie/discussion/comment/120279889#Comment_120279889

The tiler is asking for a sand and cement finish on the walls to facilitate heavy 60x120 walls so unfortunately I don’t think these would be an option…

Included a diagram of the depth of the charger.

meercat · 23-02-2023 8:22pm

https://www.boards.ie/discussion/comment/120279889#Comment_120279889

This

and tiling should be enough

ive always used a 25mm pd box with no issues

that depth given is for a surface box.

or try reposting it to a stud wall.

jumbone · 24-02-2023 9:47am

Ok tiling... well then you only need to chase the block by 47mm - (thickness of sand & cement coat + thickness of tile adhesive+ thickness of tile)

and if that isn't enough, there's always the likes of https://www.screwfix.ie/p/2105j

Doolittle51 · 26-02-2023 8:25am

There's no issue chasing out back boxes to 47mm. If the wall is being tiled, the back box could be left proud by about 10mm, so only really a 37mm cut out required anyway.

Would it not be easier to charge the toothbrush some where else? At some point the toothbrush will break and you'll be left with a charger in the bathroom that has no purpose.

kirk. · 26-02-2023 1:58pm

https://www.boards.ie/discussion/comment/120289517#Comment_120289517

Just rereading it there thought it was a shaver socket

Hardly worth the bother for a toothbrush charger

07-03-2023 10:32pm

TBH, a lot of those devices are designed for North American plasterboard/drywall style construction where knocking a hole in the wall is a trivial matter.

It can be a major ordeal in Ireland or most of Europe.

47mm Electrical backbox - Block Wall

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