When drilling floor joists to run 2.5mm twin and earth or 4 core flex,do I need to drill a seperate hole for each cable or can I make a slot for them-3 in total, cables are for a fused spur for a boiler by the way. Thanks
drilling floor joists
- Thread starter chr15
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S
sparky40
Hello.
One hole (drilled in the correct zone) is fine.
One hole (drilled in the correct zone) is fine.
Flexible cables should not be used for fixed wiring eg under floors.If it is for an appliance run a twin and earth cable and terminate in a box with coverplate and connectors then run flex to appliance.If you need 4 cores then run 2 twin and earth cables and terminate the same way with 4 core flex.As for the holes in joists as long as the cables move through easily with no chaffing/burning then you can put as many as you like through a single hole
ricicle
ricicle
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Flexible cables are perfectly acceptable for use as fixed wiring as per the regs. Ricicle - can you quote me where the regs forbid flex as fixed wiring?
Methinks you are quoting from the 15th Edition...
Methinks you are quoting from the 15th Edition...
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So does that mean it is ok to run 4 core flex under the floorboards?-not that anyones going to see but trying to do things right but I seem to get different answers from different sparks.
Can you tell me where it says you can.All the sparks ive ever known have frowned upon it!
Not so sure about slots in joists. IEE (and Building) Regs apply as follows:
where cables are run beneath boarded floors, they must pass through holes drilled in the joists which are at least 50 mm below the top surface of the joist. This is to prevent accidental damage due to nails being driven into the joists. The hole diameters must not exceed one quarter of the depth of the joist and they must be drilled at the joist centre (the neutral axis). Hole centres must be at least three diameters apart, and the holes must only be drilled in a zone which extends 25% to 40% of the beam length from both ends.
TTC
where cables are run beneath boarded floors, they must pass through holes drilled in the joists which are at least 50 mm below the top surface of the joist. This is to prevent accidental damage due to nails being driven into the joists. The hole diameters must not exceed one quarter of the depth of the joist and they must be drilled at the joist centre (the neutral axis). Hole centres must be at least three diameters apart, and the holes must only be drilled in a zone which extends 25% to 40% of the beam length from both ends.
TTC
securespark said:
15 All.
Who's gonna serve the ace?
The no flex was removed from the regs. I think it should have stayed in though.
You may not put many cables in holes with derating them. In this particular case just for a boiler it might be OK though
You may not put many cables in holes with derating them. In this particular case just for a boiler it might be OK though
OK game set match to Securespark. Reg 521-01-04.I looked it up today,but yes it was not permitted in the 15th and I agree with ebee it should have stayed that way,but the up to date regs are our bible.
Full marks to Securespark
Ricicle
Full marks to Securespark
Ricicle
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It's putting us in line with mainland europe, where they use flex as fixed wiring ATT.
Along with harmonised colours,to enable our Eastern European brothers to come over here and work!
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