Cable run under floorboards

[Iain123]

Hi Group

Had a third party inspection by a NAPIT tester, to get building control approval for a pv installation.
He has failed the cable run in Twin and Earth under my floorboards even though its greater than 50mm from surface. No 30ma RCD fitted to this circuit.

I though it was acceptable if the cable was 50mm or greater from the top of the joists?
Thanks for advice in advance

Iain

 

[7029 dave]

Yes I would if necessary, same as I have done in the past.

Been in this game since 1979, and I can say never have, always drilled out timbers.

 

[davesparks]

Been in this game since 1979, and I can say never have, always drilled out timbers.

I've been in the job for 11 years and I've had notches cut in to timbers a few times.
It's always been on buildings with exposed timbers and ceilings fitted between timbers rather than below them. When you've only got an inch gap between the bottom of the floor and the top of the ceiling you don't really have much other choice. These have been new extensions to grade 1 listed buildings.

 

[Leesparkykent]

https://www.tlc-direct.co.uk/Main_I...Index/Necessities~Cable_Protection/index.html

For when you have to notch a joist.

 

[davesparks]

I hadn't realised they were NICEIC approved,
I'll have to stop using them now!

 

[7029 dave]

Yes I would if necessary, same as I have done in the past.

Skill sawed through an 6mm cooker circuit, notched, blew me blade to bits, an set blade just at floor board level.

 

[Leesparkykent]

I hadn't realised they were NICEIC approved,
I'll have to stop using them now!

Have your own ones made then you don't have to worry about the NICEIC approval :wink5:

 

[DPG]

They don't look very thick those plates - I'm trying to remember if there was a minimum thickness requirement. Daz

 

[DPG]

Actually, just I've just checked reg 522.6.204 and it just states 'sufficient to prevent penetration (oo err) of the cable. Daz

 

[DuaneMHunt1976]

So 522.6.100 of BS7671:2008 (2103) has moved to 522.6.201 & 522.6.204 in BS7671:2008 (2015)

Well done finding the Move DPG

 

[telectrix]

Skill sawed through an 6mm cooker circuit, notched, blew me blade to bits, an set blade just at floor board level.

if you cut floorboards with a chainsaw, then you deserve it.

 

[Guest77]

Been in this game since 1979, and I can say never have, always drilled out timbers.

Same here, I have on the odd occassion used a plate, that has usually been when rewiring and there is slots from old central heating pipes available and it is a bit dangerous to drill further holes due to weakening the joists, otherwise I always drill everytime and thought everyone else did also.

 

[davesparks]

Same here, I have on the odd occassion used a plate, that has usually been when rewiring and there is slots from old central heating pipes available and it is a bit dangerous to drill further holes due to weakening the joists, otherwise I always drill everytime and thought everyone else did also.

As I said above, on extensions to listed buildings where traditional building styles are used and most of the joist remains exposed and just an inch of void above the ceiling panels you don't have anywhere to drill