Using external wall cavity to carry 2.5mm T&E cable
 

Hi
I think the subject explains most of what I'm looking to do.
I need to add a double socket and the best place for the cable is the
wall cavity. The socket is on an exernal wall on the ground floor which
has floorboards. The wall cavity is insulated but not with polystyrene
balls.
Apart from the various rules saying it's an undesirable situation, are
there any tips to accomplish said task? Was going to drill at a downward
angle into the cavity from where the socket will be, and hope to pick up
the cable into a hole into the cavity under floorboard level. I was
intending to have a bigger diameter hole under the floor and use a hook
to pull the cable through, assuming it ever feeds into the right
location! Could protect holes to avoid damaging cable when pulling through.
Any other tips? Ta.

Using external wall cavity to carry 2.5mm T&E cable
 

On 11/11/2019 13:58, Grumps wrote:
Hi
I think the subject explains most of what I'm looking to do.
I need to add a double socket and the best place for the cable is the
wall cavity. The socket is on an exernal wall on the ground floor which
has floorboards. The wall cavity is insulated but not with polystyrene
balls.
Apart from the various rules saying it's an undesirable situation, are
there any tips to accomplish said task? Was going to drill at a downward
angle into the cavity from where the socket will be, and hope to pick up
the cable into a hole into the cavity under floorboard level. I was
intending to have a bigger diameter hole under the floor and use a hook
to pull the cable through, assuming it ever feeds into the right
location! Could protect holes to avoid damaging cable when pulling through.
Any other tips? Ta.

You can make it easier to catch the cable by pushing a doubled tape
measure into the hole so that is spreads out against the outer leaf.

Using external wall cavity to carry 2.5mm T&E cable
 

On Monday, 11 November 2019 13:58:55 UTC, Grumps wrote:
Hi
I think the subject explains most of what I'm looking to do.
I need to add a double socket and the best place for the cable is the
wall cavity. The socket is on an exernal wall on the ground floor which
has floorboards. The wall cavity is insulated but not with polystyrene
balls.
Apart from the various rules saying it's an undesirable situation, are
there any tips to accomplish said task? Was going to drill at a downward
angle into the cavity from where the socket will be, and hope to pick up
the cable into a hole into the cavity under floorboard level. I was
intending to have a bigger diameter hole under the floor and use a hook
to pull the cable through, assuming it ever feeds into the right
location! Could protect holes to avoid damaging cable when pulling through.
Any other tips? Ta.

It can be a pain getting hold of the cable at the lower end.

Using external wall cavity to carry 2.5mm T&E cable
 

Grumps wrote:

Hi
I think the subject explains most of what I'm looking to do.
I need to add a double socket and the best place for the cable is the
wall cavity. The socket is on an exernal wall on the ground floor which
has floorboards. The wall cavity is insulated but not with polystyrene
balls.
Apart from the various rules saying it's an undesirable situation, are
there any tips to accomplish said task? Was going to drill at a downward
angle into the cavity from where the socket will be, and hope to pick up
the cable into a hole into the cavity under floorboard level. I was
intending to have a bigger diameter hole under the floor and use a hook
to pull the cable through, assuming it ever feeds into the right
location! Could protect holes to avoid damaging cable when pulling through.
Any other tips? Ta.
You may need to use something like fencing partly hardened steel wire to
force it through the edge of an insulation batt if you are unlucky. It
may need derating for being insulated, an electrician will tell us if
it is ok for a 32A ring.

--

Roger Hayter

Using external wall cavity to carry 2.5mm T&E cable
 

In my daughter's new build the meter tails run approx. 3m in the cavity from the external meter box to the CU. When the houses were being built the external walls were cavity insulated with foam sheets so I presume a channel was left to feed the cables through.

Richard