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An odd question granted but bear with me.

I've got to extend a radial circuit in a community centre to fit a new hand dryer in the toilets, but I have two restrictions.

1. It's a listed building so I'm not allowed to damage the walls in any way.
2. Even if I could, I've been told there is asbestos in the wall cavities, so I couldn't drill into them anyway.

So, nearby there is a flush mounted single socket on a 20A radial. The easiest way would be to run some nice D-Trunking from that socket around the wall and into the toilet area where I can surface mount a switched fused spur for the hand dryer. Jobs a gooden. However it's a flush mounted socket, so to make a nice neat job I need to convert it to a surface mounted box, so I can neatly fit the trunking to it.

I suppose the first question is can it be done ? Currently in the wall is a 25mm metal back box. If I could find a way to screw a surface mounted box to it, then that solves the problem and I can fill any pasterwork gaps. I suppose I could very carefully drill out the fixing points from the back, that could allow a long fixing screw through the front plate, surface box and into the metal back box, but that seems to be a bit of a faff.

Is there anything on the market designed for this very job ?
 
I suppose I could very carefully drill out the fixing points from the back, that could allow a long fixing screw through the front plate, surface box and into the metal back box, but that seems to be a bit of a faff.
Why a bit of a faff? No more so than having to drill and rawlplug to holes on a brick wall!
 
The other thing occurring to me is if you can't screw the D-Line to the wall and can't secure the cable inside it using anything fire rated then premature collapse could be considered to be an issue.
In a listed building they would usually be obsessed with anything fire related and they may have to revise the method of working statement, or consider a different cable route.
 
Aren't there semi pattress boxes available, intended for using where a fitting is to deep to mount into the flush box fitted, such as some dimmer switches into 16mm boxes?
Would one of these bring the existing socket out enough for D line, especially if the socket was one with a nice thick faceplate, like Crabtree 4304?
 
Aren't there semi pattress boxes available, intended for using where a fitting is to deep to mount into the flush box fitted, such as some dimmer switches into 16mm boxes?
Would one of these bring the existing socket out enough for D line, especially if the socket was one with a nice thick faceplate, like Crabtree 4304?
https://www.screwflix..com/p/schneider-electric-lisse-1-gang-spacer-white/5782j
They tend to be 10mm.
 
The other thing occurring to me is if you can't screw the D-Line to the wall and can't secure the cable inside it using anything fire rated then premature collapse could be considered to be an issue.
In a listed building they would usually be obsessed with anything fire related and they may have to revise the method of working statement, or consider a different cable route.
Basically I'm going to have to use the self adhesive D_Trunking, and screw metal clips inside them, but ensure any hole I drill or screw I use doesn't penetrate any deeper than the drywall. Now I know the thickness of the drywall from being able to measure it elsewhere. Hate discovering there's asbestos in a building, it's a pain in the backside. The other alternative could have been using the subfloor (ie the main floor of the community centre is raised on brick peers on a concrete base, but typically the toilet block was built later without a subfloor - it' solid !!
 
Basically I'm going to have to use the self adhesive D_Trunking, and screw metal clips inside them, but ensure any hole I drill or screw I use doesn't penetrate any deeper than the drywal
Normally I'd suggest wall-dog screws as you are not pulling any material out. However they will definitely be deeper than the dry wall.
 
Normally I'd suggest wall-dog screws as you are not pulling any material out. However they will definitely be deeper than the dry wall.

You still need to drill a hole to put them in.


Edit: I now realise you were referring to their use in dry wall, which isn't something I'd have considered when cheap fixings exist for that very purpose.
 
What about GripIts? They have wings which anchor in the gap behind the plasterboard. Very good in the right circumstances.
 
An odd question granted but bear with me.

I've got to extend a radial circuit in a community centre to fit a new hand dryer in the toilets, but I have two restrictions.

1. It's a listed building so I'm not allowed to damage the walls in any way.
2. Even if I could, I've been told there is asbestos in the wall cavities, so I couldn't drill into them anyway.

So, nearby there is a flush mounted single socket on a 20A radial. The easiest way would be to run some nice D-Trunking from that socket around the wall and into the toilet area where I can surface mount a switched fused spur for the hand dryer. Jobs a gooden. However it's a flush mounted socket, so to make a nice neat job I need to convert it to a surface mounted box, so I can neatly fit the trunking to it.

I suppose the first question is can it be done ? Currently in the wall is a 25mm metal back box. If I could find a way to screw a surface mounted box to it, then that solves the problem and I can fill any pasterwork gaps. I suppose I could very carefully drill out the fixing points from the back, that could allow a long fixing screw through the front plate, surface box and into the metal back box, but that seems to be a bit of a faff.

Is there anything on the market designed for this very job ?
Regarding fixings to the wall, I would be careful and perhaps experiment with any fixing solutions you wish to try on some sample materials. If your customer tells you that any wall cavity could contain asbestos, I would consider the risk of penetrating the cavity to be high, even with trying one's best not to do so.

The building should have an asbestos register/survey detailing what ACMs have been indentified and their location.
This should explain what the issue with the walls is. For example some partition walls constructed from AIB or perhaps loose-fill insulation has been used in voids which could have contaminated inside the walls.

HSE has recently launched a new campaign to raise awareness of asbestos, reinforcing the message that there is no safe level of exposure. We should be mindful that when disturbed incorrectly, "at best" it will disperse to a low concentration, it does not go away, it does not ever breakdown into something safe. Clients often need education about this.
In a non-domestic premises there are legal duties on the owners/occupiers from the Control of Abestos Regulations to manasge it safely.
Also as tradesmen we are bound by the same regulations when working in any premises.


If a non-domestic client cannot provide such information and there is a known or suspected risk, I would probably not want to do the job. I realise this may feel an awkward thing to do if the community centre is a building in your locale which you are familiar with and personally know the people who run it.
 

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