wiring under floor boards

[pb8]

Hi all I've been asked to wire a friends house but it's got a space under ground floor floor boards. Can't remember ever doing one before. Do I need to put cables in tube or are they ok just resting? Can't see anything specific in big book.
Originals just lying there so I'm assuming I'm ok to do same.
Thanks all
Paul

 

[Adam]

All cables should be supported, not lay on the dirt under the house.

 

[sparks1973]

All cables should be supported, not lay on the dirt under the house.

mind you ...you see it enough times...cables just layin underfloors that is....and not just new install either.....plenty of VIR install done that way...
now...cables should always be supported...theres a very good reason for this n all..
a fault reaches full potential on the first quarter cycle.....and inclipped/insupported cables subjected to this can rupture as a result....

 

[micknew]

mind you ...you see it enough times...cables just layin underfloors that is....and not just new install either.....plenty of VIR install done that way...
now...cables should always be supported...theres a very good reason for this n all..
a fault reaches full potential on the first quarter cycle.....and inclipped/insupported cables subjected to this can rupture as a result....

Never new that, are you sure?

 

[Adam]

Many re-wires are also done that way, and I am also guilty of it.

it is not always possible to clip the cable along the full length of the joists, although I always try to wire across joists so they are supported by the holes.

However, I would never leave unsupported cables lying on the ground underneath the house.

 

[Jdsparky]

It is possible if you have to crawl on your belly under there like I did a few months ago.....was aching for a few days after mind, using muscles I never have before....end result sort of worth it that I know it was done properly clipped the whole way no sky job....I stunk afterwards from the damp down there aswell.

 

[Adam]

Crawl on your belly?

I prefer shuffling on my back, as it is easier to clip the cables when facing the joists.

 

[Jdsparky]

Tbf I did a bit of both, but there were pipes making the gap even tighter in places so had to use my toes whilst on front to move anywhere, it was a nightmare, I would then get in position then shuffle on my back to clip, whilst looking out for our eight legged friends which luckily I didn't see any thank god lol

 

[kingeri]

Nothing wrong with unsupported cable runs in ceiling voids etc. as long as the surface is reasonably smooth and not likely to damage the cable. In domestic work it's often the only option!

 

[Guest55]

a fault reaches full potential on the first quarter cycle.....and inclipped/insupported cables subjected to this can rupture as a result....

eh ? never heard of a cable blowing itself apart because it wasnt supported during a fault - unless you can provide a credible source to back up that claim , i call bull lol.
;-)

 

[telectrix]

could be acids or stuff in the soil that attacks the cables. cables should be clipped to the joists, even if you can only get a few in. a skinny apprentice comes in handy here.

 

[Guest55]

a skinny apprentice comes in handy here.

or a tiny terrier with a cable clip pouch around its collar. :-D

 

[DurhamSparky]

Did a rewire recently where previous sparks had jb's laid on ground..

Only became a rewire when I changed the cu to rcbo's

Plenty of void space underneath to climb down and clip (about 4 ft ) end result was happy Rcbo.

 

[cbw]

I for one am not going into the floor voids of old houses.

100 years of rat excrement and God only knows what else.

Risk assesed and sorry cables supported by ground.

 

[Richard Burns]

Slide the cables into conduit and support he ends does not meet the support intervals but protects that cable and avoids going under the floor and protects the cable