metal back boxes, back to back

[brizospark]

Currently working on a large commercial renovation where the joiners are putting up new partition walls, double sheeted each side.

We have got the joiners to put dwangs in place for us to mount our socket back boxes (metal KO boxes 35mm)

As per the drawing we basically mounted the sockets back to back on the dwang and plan to drill through the dwang to link the sockets which are on the same circuit.

However, today the site agent came to see us and claimed that sockets should never be mounted back to back

Can anyone tell me the reason for this?

 

[Engineer54]

If the place burns down just remember who's name will be on the test sheets!

Very interesting, ....So what's this all about then ??

 

[brizospark]

sorry edited as put the wrong post up!

 

[Mark_Burgess]

You will have to put intumescent gaskets in both the boxes as you have basically broken the fire barrier, I am sure screw fix sells them or TLC

 

[brizospark]

fair enough but would that not also be the case if the sockets were not back to back but say 150mm apart?

 

[Guest112]

yes probably the fire barrier issue as above said you can get the putty aswell (unless thats what he said)

 

[Mark_Burgess]

screw fix part 55229

You should really, I use the steal dry lining boxes with the intumescent gasket already fitted from TLC in circumstances like that.

 

[brizospark]

so this still doesn't answer the question as to why they have stipulated specifically no back to back boxes

 

[Guest112]

fair enough but would that not also be the case if the sockets were not back to back but say 150mm apart?

Yes if it is a fire barrier wall all electrical backboxes will require the putty/gasket inside, did on a job i done recently the project manager informed us of all fire barrier walls to seal up the bboxes

 

[Mark_Burgess]

so this still doesn't answer the question as to why they have stipulated specifically no back to back boxes

They can stipulate what they want I suppose, but it will be for fire and acoustic reasons, look at the tlc site for Fire & Acoustic Metal Dry Lining Boxes.

 

[brizospark]

they aint cheap! think we have about 250 to do