cable sheathing in stud wall dot and dab

[Chrishands]

Hi all,
Just reading my OSG today in class and we was talking about sheathing cables in stud walls. Looking at 7.3.2
i have left slightly more confused than starting the subject. can somebody clarify.
Do you need to sheath cables that are within the ''safe zones''? if not do the cables in the safe zones need to be not only in the safe zones but also 50mm below surface to qualify for not needing sheathing. when part iv talks about the installation needing ''mechanical protection sufficient to prevent penetration of the cables by nails, screws and the like, then how does plastic sheathing provide this? surely plastic sheathing is pointless.

please have patients with me as im still learning.
Regards,
Chris

 

[SPARTYKUS]

The forum search function will throw up lots of answers!

 

[jackhammerJIM]

how long is the course chris ?

 

[Octopus]

Hi all,
Just reading my OSG today in class and we was talking about sheathing cables in stud walls. Looking at 7.3.2
i have left slightly more confused than starting the subject. can somebody clarify.
Do you need to sheath cables that are within the ''safe zones''? if not do the cables in the safe zones need to be not only in the safe zones but also 50mm below surface to qualify for not needing sheathing. when part iv talks about the installation needing ''mechanical protection sufficient to prevent penetration of the cables by nails, screws and the like, then how does plastic sheathing provide this? surely plastic sheathing is pointless.

please have patients with me as im still learning.
Regards,
Chris

Are you in a hospital ward?

 

[Darkwood]

Use the correct terminology first ...by sheathing a cable you could mean capping which is really only needed to stop the plasterer damaging the cables with the edge of his float.. are we discussing providing mechanical protection for cables here?

 

[pjcomp]

Capping/sheathing won't stop nails or drills - try it sometime (not with live cables!!) - it's only useful for keeping plaster and plasterers away. So if installing cable which will be behind dot'n'dab plasterboard there's no "must have" for capping, and no need for mechanical protection if it's in safe zones.

pj

 

[Deleted member 72666]

please have patients with me as im still learning.

Are you in a hospital ward?

That made me laugh!

 

[Chrishands]

2 years

 

[SPARTYKUS]

Darkwoods summed it up. But you will be bombarded throughout your career by muppets that think they know different

 

[Chrishands]

can i just state that i do know the difference between patients and patience. Although i did get it wrong earlier! Thanking myself for the humour

 

[Knobhead]

As you can't give yourself a thanks I will. Not a lot makes me chuttle on here.

 

[Chrishands]

Darkwoods summed it up. But you will be bombarded throughout your career by muppets that think they know different

My grandad a builder already commented on it when i was putting in a simple fused spur. I had to agree it did feel so wrong to not even put a little bit of plastic capping. I put some in, but i knew it was in the safe Zone! :banghead:

 

[SPARTYKUS]

My grandad a builder already commented on it when i was putting in a simple fused spur. I had to agree it did feel so wrong to not even put a little bit of plastic capping. I put some in, but i knew it was in the safe Zone! :banghead:

Its not the safe zone so much - its if the wall is being ' backed out' instead of dot and dab. Safe zone or not, it needs to be capped as the trowel is likely to clip the cable.

if you are rewiring a house and cut a deep groove in the existing plaster/wall, for the new cable to sit in, and it is firmly fixed inside and well below the surface, then again, capping is debateable as the spread would have to be really trying to damage the cable!

plastic oval conduits the best job. Especially for the next spark.