Help with cable routing through loft?

[HappyHippyDad]

Hello all,

I will be having my assessment on Oct 11th and have completed a CU change and also an addition to a lighting circuit. I am completely happy with the CU change but am unsure about the cable routing in the loft for the lighting addition.

At present all the cables in the loft simply run over the top of the joists (without a notch) and then under the insulation. I understand all the regs regarding going through joists and also about size of notch you are allowed to cut on the top, but my question is ..Is it ok to just have the cables running over the top of each joist? (i.e perpendicular)

Thanks.

 

[telectrix]

it's OK if they are run in a position where they are not likely to suffer damage. e.g. by walking on or stuff being piled on top. usually OK if routed under the low part of the roof, towards the eaves. if in a vunerable position, a run of steel capping over the top could be a solution.

 

[Strima]

I wouldn't have them running over the joists due to the risk of damage when someone is either working up there or just throwing stuff up there. Is there scope to fit batons to the roof timbers and clip the cables to them? Also a bit of waste/drain pipe to keep the insulation away from the cables where they drop for switches/roses etc.

 

[HappyHippyDad]

Thanks both,

I think it would be safe Telectrix as they are running near the eaves where the roof is much lower, however I've found a couple of past posts and like you suggest Strima they say pass a baton along and clip to that or just take the cable all the way to the edge and then along and back the joist near my exit point.

I think I'll run a baton.

Cheers guys

 

[Top Cat]

As the others have said but to be quite honest i have never had an inspector bother to go up in the roof space yet. So from that point of view i would not worry too much.

If he really wants to go up and see, tell him that there is a live wasps nest up there!

 

[Octopus]

As the others have said but to be quite honest i have never had an inspector bother to go up in the roof space yet. So from that point of view i would not worry too much.

If he really wants to go up and see, tell him that there is a live wasps nest up there!

Thats all very well, but are you really promoting a policy of don't worry about the workmanship and application of the regs to the parts the assessor won't see?

 

[Top Cat]

Thats all very well, but are you really promoting a policy of don't worry about the workmanship and application of the regs to the parts the assessor won't see?

Sorry Murdoch, next time i will put in brackets (tongue in cheek)!

 

[Des 56]

At present all the cables in the loft simply run over the top of the joists (without a notch) and then under the insulation

That would account for 95% of households in the UK, if not more

 

[HappyHippyDad]

At present all the cables in the loft simply run over the top of the joists (without a notch) and then under the insulation

That would account for 95% of households in the UK, if not more

Now thats interesting. 95% of electricians cant be wrong, so it cant be too bad! i'm still going to put a baton in though

 

[Des 56]

Now thats interesting. 95% of electricians cant be wrong, so it cant be too bad! i'm still going to put a baton in though

Now your reading too deeply into my words HHD I did say installations :smile5:
Electricians make up the majority but a very big minority are a.n others


i'm still going to put a baton in though
By all means,you do the jobs as you see fit and good on you for doing so
Others may feel fixing batons in an attic is not the greatest priority :flowers:

 

[HandySparks]

If it's a modern house with factory-made wooden trusses, and "joists" only 100mm high, I would NEVER drill or notch them.

If the wiring is T&E for lighting on a 6A breaker, then don't worry about insulation. Even if completely surrounded by insulation, the CCC will be adequate.

 

[keniff]

If the wiring is T&E for lighting on a 6A breaker, then don't worry about insulation. Even if completely surrounded by insulation, the CCC will be adequate.

That's what I always say about lighting cables, never bothered about the insulation on them

 

[worzol99]

In more modern houses loft/attics are not that big anyway so why the need to notch? i was always taught take a square cable route so you haven't got to go over joists in the middle.. but with the price of cable these days..