Solutions for Surface mount to conduit.

[westward10]

How are they rigidly joined, they aren't it contact with each other.

 

[7029 dave]

Why can't you put a surfaced mounted box , with knock outs then away you go.

 

[Andy78]

Like a said being picky but there is no containment for the conductors between the existing back box and the new box aside from butting them together.

What potential issues can you see arising from this ?

 

[Octopus]

How are they rigidly joined, they aren't it contact with each other.

So the metal box is in the ball and the surface box is attached firmly to the wall - whats the problem?

You HAVE to apply common sense. Its not as it we were talking about metal containment and lack of continuity.

 

[Midwest]

Give me an instance where a door may not be an escape route. If you have passed through it there may be a requirement for you to pass back through it an emergency situation, even the door to a toilet cubicle. You are sitting on the loo and the fire alarm goes off that cubicle door is your escape route, far fetched but true.

Going a bit off tangent.....but.

I don't do commercial/industrial, so my exposure to escape routes is limited. However, premises covered by The Regulatory Reform (Fire Safety) Order 2005 (FSO) & Fire Precautions (Workplace) Regulations 1997 etc, perhaps as the picture posted, require the designation of escape routes as part of the risk assessment for those premises. So it would easy for an installer to identify 'such doors', by referring to the documented risk assessment for the premises.
I would suggest a door to an airing cupboard, would not be, but at the other end of the scale, a door to the outside would form part of an escape route. To simply state a door, as per definition, most be part of an escape route, would make a premise unviable in terms of all the other paraphernalia & equipment required.

So yes, there will be doors that do not form part of an escape route, designated for escape to a place of safety in the event of an emergency.

 

[westward10]

What potential issues can you see arising from this ?

None just wanted other people's views on it, I have often thought there is that no man's land between the two enclosures.

 

[mattg4321]

My view is you're probably bored and trying to create conversation where there is none to be had. You're going on about containment but why would this enclosure not meet the relevant IP ratings?? It looks pretty good to me. If you first fix a property and come back to find the plasterer has added an extra 10mm depth of plaster, I presume you remove all your KO boxes and pack them out by 10mm?

 

[westward10]

My view is you're probably bored and trying to create conversation where there is none to be had. You're going on about containment but why would this enclosure not meet the relevant IP ratings?? It looks pretty good to me. If you first fix a property and come back to find the plasterer has added an extra 10mm depth of plaster, I presume you remove all your KO boxes and pack them out by 10mm?

I was genuinely curious because I have been asked this in the past and thought it was an opportunity to get other views. If a plasterer has added to the depth of plaster then you should fit back box spacers.

 

[HandySparks]

None just wanted other people's views on it, I have often thought there is that no man's land between the two enclosures.

Take a look at 526.5 iii:
Every termination or joint...shall be made within one of the following...An enclosure partially formed or completed with building material which is non-combustible...

 

[mattg4321]

Don't want to be rude but we're going to have to agree to disagree here.

A back box spacer at 10mm deep? I've not seen one of them.

 

[HandySparks]

...then you should fit back box spacers.

Got any pics or examples of spacers for flush boxes?

 

[mattg4321]

You can get them but Ive only seen them in 16,25,35mm deep.

UK Elecrical Supplies - https://www.ukelectricalsupplies.com/norslo-extension-steel-boxes-2-gang-16mm.htm?utm_source=google&utm_medium=shop&utm_campaign=feed&gclid=CKr3mYbkpdACFQ8TGwodZVYMsQ

You'd have to be a complete fruitcake to go round a whole house fitting them though, just because a plasterer has added a bit more depth to the plaster.

 

[Pat H]

How is a light switch different? The back box is often behind the plasterboard so the switch and backbox aren't together the plasterboard is sandwiched between.

 

[Diddy]

You can get them but Ive only seen them in 16,25,35mm deep.

UK Elecrical Supplies - https://www.ukelectricalsupplies.com/norslo-extension-steel-boxes-2-gang-16mm.htm?utm_source=google&utm_medium=shop&utm_campaign=feed&gclid=CKr3mYbkpdACFQ8TGwodZVYMsQ

You'd have to be a complete fruitcake to go round a whole house fitting them though, just because a plasterer has added a bit more depth to the plaster.

Actually we used to fit loads of these when needed. More when you have 50-100mm gap between back box and finished wall. Weather that is because of plaster or over enthusiastic laborers doing mad chases or even the odd occasion where you get industrial type partition walls which can be well in excess of 100mm thick ect....plenty of uses - bloody things used to give me nightmares as an apprentice due to it being "My job" lol.

But as for the "containment issue" mentioned above - I think surface mounted onto wall on top of flush box is absolutely fine - fabricated containment using building fabric meets all ip requirements ect.....If we were talking about inside an explosive environment then we may have a shout for a "better" solution...but that really is being pedantic lol.

 

[davesparks]

Well this is an exciting thread isn't it, filled with interesting technical discussion and a chance for us all to learn something!

I think the OP and I are going to get on like a house on fire

 

[Andy78]

Ey up Dave, how's it going ?

 

[Rpa07]

He's back! Ears were itching, got his own thread an' all.

 

[7029 dave]

Well this is an exciting thread isn't it, filled with interesting technical discussion and a chance for us all to learn something!

I think the OP and I are going to get on like a house on fire

HA HA , been busy with the fireworks Dave.

 

[davesparks]

Any other neat solutions to get from below surface to over surface conduit?

Assuming you are talking about t&e or other sheathed cable then its often easier to use mini trunking in such a situation, just butt it up to the existing socket and drill through into the flush box.
For a proper conduit job then chop the wall out a bit and use a double set to get the conduit below the surface of the wall, then just coupler and bush or two lockrings and bush into the flush box

 

[davesparks]

HA HA , been busy with the fireworks Dave.

Very busy yeah, plus a lot of other things