metal pattress boxes.

[bigegg]

I have a lot of metal pattress boxes (doubles) which I want to use in my shed/garage/workshop.
they are the sort which are normally sunk into the wall, and plastered around
the shed is osb/chipboard lined, with a mixture of rock wool, polystyrene, and expanded foam insulation.
some of the sockets will be wall mounted, some set at an angle on the work bench (like school science labs), and some on the front of benches. (a couple also in cupboards, and 3 or 4 doubles on ceiling joists).


would they be ok mounted in a wooden box? or do they need a fireproof/plasterboard surround?

budget won't stretch to the proper metal clad sockets, and the plastic boxes tend to get broken.
I have about 30 double sockets already, so costs of anything else would be significant. I'm planning on around 25 double sockets around a 20x10 garage, then another 5 in a separate 10x10 shed.

30a supply, on its own breaker box from meter.
I work alone, so there'll only be two or three sockets on at same time (compressor, plasma cutter, floodlight is probably highest concurrent load). it's just for convenience, so I can have everything plugged in, ready to use instead of swapping and changing.

 

[eLuSiVeMiTe]

https://www.screwfix.com/p/variligh...HObEo4bNSkdaOp42jy8aAiRGEALw_wcB&gclsrc=aw.ds

Don't see why not.

 

[cheb]

As long as they are earthed and all the knock outs are in place why not? No different to a metal clad box, just more hipster.

 

[TechnicAl]

I used plastic....no breakages and they have been in for 2 to 20 years

 

[angellonewolf]

If your going the wooden box method why not build a run around the shed like trunking to seat the boxes in and then you can run cables in as well screw on a cover?

 

[angellonewolf]

wooden version like this

 

[bigegg]

If your going the wooden box method why not build a run around the shed like trunking to seat the boxes in and then you can run cables in as well screw on a cover?

that's the plan in places.

 

[brightspark]

that's the plan in places.

don't bother trying to put metal boxes in the 4 inch trunking you need the clip in back boxes . more trouble than its worth just shell out and use surface plastic ones that fit the sockets .job done

 

[bigegg]

don't bother trying to put metal boxes in the 4 inch trunking you need the clip in back boxes . more trouble than its worth just shell out and use surface plastic ones that fit the sockets .job done

I'm not using 4in trunking.
I'm building wooden boxes to mount them in.

 

[Al Strachan]

i'de still choose buying plastic dry lining boxes over using free metal boxes. Appleby ones are by far the best (in my opinion)

 

[bigegg]

i'de still choose buying plastic dry lining boxes over using free metal boxes. Appleby ones are by far the best (in my opinion)

works out at just over £32 for 30 dry line boxes, so not as bad as I thought.

was thinking it would be nearer£100, but I had been looking at "metal clad" boxes.


thanks.

 

[Dee J]

No problem whatever in what you're doing. If you want to enclose metal back boxes in timber then the hazard will be minimal. Certainly no greater than the same boxes installed in wooden studwork in partition walls.

 

[bigegg]

what's the minimum thickness of board that a drylining box will "grip"?
I'm looking at images, and some look like they'll tighten up to next to nothing, others look like they're 10-15mm back from the front edge.

I'm using 4mm ply for the fascia

 

[Al Strachan]

i have some appleby boxes at home i can measure, but from experience, its very easy to cut small packers and glue to the back of the board where the lugs grip. (still easier than metal boxes)

 

[bigegg]

i have some appleby boxes at home i can measure, but from experience, its very easy to cut small packers and glue to the back of the board where the lugs grip. (still easier than metal boxes)

the plan with the metal boxes is to cut rectangular holes in tbe fascia slightly smaller than the backbox, then drill holes for the faceplate screws and trap the plywood between the face, and the box.

easy enough to do with a template + router + drill - easier than adding Packers.

 

[Al Strachan]

appleby state grip range of 6.35mm to 15mm

 

[Burdekin]

Part of my workshop has trunking and then some has moulded boxes externally. The new section has all new external plastic boxes, I didn't want the faf of running wires behind walls/ceilings so Gaz has made trunking from timber and mdf to run in wall/ceiling corners.

https://www.screwfix.com/p/2g-moulded-box-32mm/8179d

 

[zx9]

the plan with the metal boxes is to cut rectangular holes in tbe fascia slightly smaller than the backbox, then drill holes for the faceplate screws and trap the plywood between the face, and the box.

easy enough to do with a template + router + drill - easier than adding Packers.

Strictly speaking your metal boxes should be screwed to wooden noggins such that they are flush with the finished face of the timber this maintaining a fire resistant enclosure. Plaster board would be different as it is considered to be fire resistant, should the metal box be below the back face of the plaster board longer than normal screws used to be fitted to make up the gap, these days a metal collar is fitted to make up the gap.
Note on the above:
I am not a sparkie, the above is based on requirements we have to work to when installing LV signal and data cables in public buildings.

 

[AndySV1K]

55p each (+vat) for 10+ here...

https://cpc.farnell.com/pro-elec/19679d/double-dry-lining-box/dp/PL04304?st=dry lining box

 

[Al Strachan]

some dry lining boxes can either be very hard to click in the lugs, neigh on impossible to remove without destroying, or the lugs dont stay firm enough in place to screw into. Also the brass inserts can pull out easily on the cheaper ones.

I "house bashed" for 10 years, and have deep hate for any dry ling box that isnt Appleby, some are better than others though. They will all likely work