Extending sockets through 50mm thermal insulation boards

[Pookey]

I am fitting 50mm thermal insulation boards on to the Walls and have removed socket face plates and cut an area out of the boards at each socket. I am now unsure how to extend the socket box through the insulation boards. I was going to use terminal blocks to extend the wires and use back box extentions but they don't seem to exist! I can't
just use longer screws as this is a fire hazard according to the manufacturer of the boards. Also, what amp terminal blocks do I use - 3,5,15 or 30amp.

Thanks

 

[holmslaw]

..

 

[sparkwright]

Can you obtain any slack on the cables so you don't have to extend them?

Or can you just move the sockets a few inches up or down to gain a bit more length on the cables?

If you do this you could fit 47 mm boxes directly to the old wall.

I assume you then plasterboard over the insulation board.
You could cut dry-line boxes into the finished plasterboard.

 

[Pookey]

The insulation boards already have the plasterboard attached and I have already cut out the sockets but I could maybe move sockets up on the other rooms that have t had the board up yet. Is a dry lined box just plasterboard? If so, how do you attach the front socket plate. I assume from your post it is not good to extend the wires?
Thanks for your help

 

[sparkwright]

deleted - advise was not good enough for the op.

Don't know why he removed that post.

Since the op has already cut the holes in the new wall, the extension rings shown by holmslaw would be a good option.

Is the old wall of brick construction or studwork?

If studwork there may be a greater chance of getting some slack on the cables.

In answer to the original post 30 amp connector blocks could be used.
Or blue in-line crimps (if 2.5 mm cable), use only the ratchett type of crimping tool. No doubt somone will send that picture again.

I imagine you will want to keep all the sockets in the house at the same height, now you have already started work.

If you ask holmslaw nicely, he may send those pictures of the extension rings again.

A dry-line box is usually a plastic box that is cut into plasterboard. Flanges grip to the plasterboard, and as the socket front is tightened, everything becomes firmly fastened to the wall.

 

[Pookey]

hi, the walls are a mixture of brick and 2 foot thick stone.

I would like to see a picture of the extensions rings again please... pretty please.

I have managed to get a bit of slack on a couple of the cables but 2 sockets wont budge. For the sockets where the wires have stretched enough, what do I line the thermal board edges with?

 

[ColJack]

to fit dry lining boxes ( as shown in pics below, rachet crimps also shown ) you will have to dig some of the foam off the back of the boards where the lugs ( the yellow bit ) grip..

View media item 22199 View media item 22200 View media item 22201View media item 22202 View media item 22203

 

[Pookey]

I have just looked at blue crimps and there are so many - male, female, looped, spades etc - what type do I need and what tool do I use to seal them. I have also found some extension boxes on ebay but only double sockets. Do you know where I will find some single extension boxes?

 

[ban-all-sheds]

I can't just use longer screws as this is a fire hazard according to the manufacturer of the boards.

¿Que?

Also, what amp terminal blocks do I use - 3,5,15 or 30amp.

What's the rating of the fuse/MCB for the circuit?

 

[Pookey]

I can't just use longer screws as this is a fire hazard according to the manufacturer of the boards.

¿Que?

Also, what amp terminal blocks do I use - 3,5,15 or 30amp.

What's the rating of the fuse/MCB for the circuit?

Cheeky...
It may be obvious to you but I havent got any electrical experience atall. That is why I am researching on this board. This is the first electrical job I have ever attempted and am looking for HELPFULL advice from experienced people. If you want advice on rearing toddlers, cooking, motherhood etc I will be more than happy to assist!!

 

[sparkwright]

http://cpc.farnell.com/1/1/43499-box-extension-1g35mm-sb681-appleby-html

 

[sparkwright]

You could fit more than one extension ring to get the right depth, or as near as you can get.

You will need the correct size cable, match up with existing. 2.5 mm is usual, so check first.

Use earth sleeving.

 

[ColJack]

you want through crimps.. wire goes in each end..

the MI overrule any other electrical regs so if they say you can't leave the foam exposed to the wires, then you can't leave the foam exposed to the wires.. foil tape ( such as used for sealing duct work ) can probably be used, but check with the manufacturer..
extension rings or fast fix boxes means you don't need this..

what is the overall thickness of the boards? 50mm foam + 9mm plasterboard? or 50mm total including the plasterboard?

add a bit for adhesive and you get either 65-70mm, or 55-60mm.. so it depends on whether to order 2 x 35 or 2 x 25 or one of each for best fit..

 

[ban-all-sheds]

Cheeky...
It may be obvious to you but I havent got any electrical experience atall. That is why I am researching on this board. This is the first electrical job I have ever attempted and am looking for HELPFULL advice from experienced people.

Yes, but honestly - 3A connector blocks on a 30/32A circuit?

If you want advice on rearing toddlers, cooking, motherhood etc I will be more than happy to assist!!

Been there, done that thanks.

Well, not the motherhood part....



Which composite board is it? Celotex PL3000, Kingspan K17/K18 etc?

Is there a vapour control layer between the foam and the plasterboard?

 

[1john]

If you want advice on rearing toddlers, cooking, motherhood etc I will be more than happy to assist!!

Why wont my 7 month old son sleep all night, why can I no longer function until ten AM and why cant i get to sleep at night, all this has started since the new addition.

You need through crimps and a ratchet crimper, use blue crimps on the 2.5mm cables (the live/phase/line and neutral) and red ones on the CPC/earth (which is 1.5mm csa in modern twin and earth)