Cavity Wall Insulation - cables in cavity

Discussion in 'General Chat' started by ldoodle, Feb 9, 2014.

  1. ldoodle

    ldoodle
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    We've been offered free CWI as part of another scheme. The company doing it came out a few weeks ago to do the checks to see if it would actually be free for us, but they didn't check routing of wires.

    It has just occurred to me that about 1.5m (maybe 2m) of our cables from the CU run in the cavity to the first floor (top of the stairs) - we had the floorboards up upstairs in the Autumn for plumbing work and you can see where they come back in. There are no cables coming out from the CU so I can only surmise they go straight out the back of it, into the cavity.

    The house was built-in the late 50s/early 60s and from what I've read this was quite common. However CWI was not around then.

    The wiring seems pretty new - there's manufacturing dates of 2012 and 2013 on it and the CU is MCB based (but doesn't look brand new)...
     
  2. DarenD

    DarenD
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    They should use cable detectors when they come to drill the holes to route the insulation through if that's what your asking.
     
  3. ldoodle

    ldoodle
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    No I meant in terms of burying the cables in all that insulation, in terms of heat and de-rating
     
  4. IronGiant

    IronGiant
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    2.5mm T&E flat cable running in 100mm insulation is derated to 21A, and the legal requirement is 20A so you should be OK. Note this is from reading up on the diynot.com for when I put in extra loft insulation so you should probably await confirmation from an electrician that the same applies to a cavity. Worse case scenario, they may recommend you upgrade the cable to 4mm.

    Note: this only applies to cable feeding your mains sockets, not if you have a shower upstairs.
     

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