Meter tails in cavity

[Rockwomble]

Hi, I have just had a quote for a new CU and meter tails. The original tails go inside the cavity for about 2 mtrs between meter and CU (cavity wall insulation was added many years ago). He said he can fix the new tails to the ends of the old ones and pull them across, ie remaining in the cavity.
Is this okey?

For some reason I was under the ipression that meter tails these days should go straight through the wall and then in plastic conduit along the inside of the wall up to the CU (Meter outside, CU in garage).

 

[stephenf8542]

is your garage joined on to your house?

 

[Rockwomble]

Yes it is, integral.

 

[stephenf8542]

Seems like hes trying not to make any more holes in your house

 

[BS3036]

What type of cavity wall insulation? Could make a difference.

 

[Adam_151]

If they will pull through alright, and you want new CU where old one is, and want to avoid 50x50 trunking on wall, then go for it, no doubt someone will call me rough though!

Alway best to have a backup plan for if they won't draw through though

 

[BS3036]

Basically you don't run pvc insulated cable through polystyrene thermal insulation, as they will react chemically. If you have Rockwool thermal insulation then this problem won't occur.

 

[thompsk]

Basically you don't run pvc insulated cable through polystyrene thermal insulation, as they will react chemically. If you have Rockwool thermal insulation then this problem won't occur.

Mother-in-law has recently had a very serious problem with transmigration of polymers, she has a park home with polystyrene sheets as insulation in the loft and when made the company let the cables lye on the poly causing the pvc to go brittle and sticky, as a result 7 years on the company now has been ordered to replace all the wiring by nic inspectors.....expensive job because there are now 30 of these type of properties on the said site where she lives all requiring rewiring....ooops whadda mistakea to makea

 

[Rockwomble]

I'm not sure what the insulation is made of, but was injected, it's white and fluffy (sounds like a little pet) and cover the existing meter tails. Is it okey to run the new tails in the same position.

 

[holmslaw]

..

 

[bernardgreen]

Inspect the old tails as they come out. If they are PVC and still in good condition then MAYBE the new tails will last as long as the old tails.

But there is possibly a difference between new foam injected around old tails ( when it may form an inert skin as it cures ) and tearing a hole through existing foam when the new tails are inserted.