2.5mm2 T&E under ground floor, floor boards

[405lines]

Hello, my first post!

I've lifted the floor boards in my Bungalow and found that there is a void between the rafters and a solid concorete floor. This area being ventilated by air bricks at both front and rear of the building.

Given the depth of the rafters drilling is not really an option .

So is it acceptable to just lay the T&E on the solid concorete floor between where I wish to bring the cables up behind the skirting board in oval conduit? If that is not acceptable for compliance to 7671 then in placing the T&E in plastic corrugated conduit laid on the concorete floor acceptable?

BTW I will be subject to a building regulation Inspection and I so I wish to get this right!

Thank you.

 

[telectrix]

how deep are the floor joists? never seen them too thin to drill. or you could clip cables to the underside of the joists.

 

[Engineer54]

Personally if it was my house i'd lay the cables on the concrete rather than drill the floor joists. Not as if anything is going to disturb or damage them is there?? Can't be any different or worse to the abominations i've seen over the years with cables resting on false ceiling!! lol!!

I'm not saying that it's what BS7671 would say, or what i would or wouldn't do in someone else's house/premises.

 

[Richard Burns]

Laying the cable on the concrete floor should be an OK installation method for T&E, you want to make sure that you are not leaving the cable hanging from the accessory leave enough cable length to minimise strain as it goes upward..
Take care if there is evidence of rodent activity as they could chew the cable, in which case it is difficult to protect fully without using metal conduit which would be OTT in most cases.

 

[Buckfast]

Clipping for support would be preferred if unable to drill joists. Problems encountered when laying straight on to concrete floor could well be from vermin which seem to like to chew easily accessed cables and also other trades,(plumbers etc who like to pull and trap your cables when installing pipes).

 

[Stroppy]

I would go for clipping to the undersides of the joists for neatness, or maybe bunched with that metal strapping stuff if you've got loads of cables all running the same way - drilling the joists seems a lot of unnecessary effort as you can go under them.