Following on from my post a couple of weeks ago about correct
positioning of halogen lights, I now have a question about the cable.

I have two 80mm * 36mm ceiling joists to cross with the 5AMP round
cable. The loft will be boarded with screwed down boards.

Do I drill something like an 8mm hole in the joists or do I notch from
the top? The lighting circuit currently has notches cut out for the
T+E in the top of each joist.

Thanks for you help.

Winged Cat wrote:
Following on from my post a couple of weeks ago about correct
positioning of halogen lights, I now have a question about the cable.

I have two 80mm * 36mm ceiling joists to cross with the 5AMP round
cable. The loft will be boarded with screwed down boards.

Do I drill something like an 8mm hole in the joists or do I notch from
the top? The lighting circuit currently has notches cut out for the
T+E in the top of each joist.

The correct way is to drill the middle of the joist.
However.
Notching adjacent to an existing notch to the same depth will have
almost zero effect to the strength of a beam.
Keep it as close as you can, ideally just widen the notch.

Ian Stirling wrote in message ...
Winged Cat wrote:
Following on from my post a couple of weeks ago about correct
positioning of halogen lights, I now have a question about the cable.

I have two 80mm * 36mm ceiling joists to cross with the 5AMP round
cable. The loft will be boarded with screwed down boards.

Do I drill something like an 8mm hole in the joists or do I notch from
the top? The lighting circuit currently has notches cut out for the
T+E in the top of each joist.

The correct way is to drill the middle of the joist.
However.
Notching adjacent to an existing notch to the same depth will have
almost zero effect to the strength of a beam.
Keep it as close as you can, ideally just widen the notch.

Thanks - I drilled the middle of the joist in the end which seemed to
be the easiest solution after all. Didn't fancy the vibrations caused
by hammering out fresh notches, what with my new ceiling just gone in.

In article ,
Winged Cat wrote:
Didn't fancy the vibrations caused
by hammering out fresh notches, what with my new ceiling just gone in.

You cut across the joist with a saw to the depth required at either side,
then tap out the waste with a sharp chisel. Being across the grain, the
waste should snap out easily. If your ceiling can't survive this I'd be
worried.

--
*Time flies like an arrow. Fruit flies like a banana.*

Dave Plowman London SW
To e-mail, change noise into sound.