Depth of chasing

[Nijinski001]

Can someone settle me an argument regarding a job we start next week.

I have an NIC leckie starting a job for me next week and he has said that according to 16th edition and the OSG there is a stipulated depth of chasing inside the zones or the cable has to be capped. i.e. vertical and horizontal from the fittings and within 15mm of the room edge.

From the OSG I have read I don't believe there is (don't have my copy at the moment) and would like the evidence to prove my point and stop him trying to dupe me into something that's not correct.

Can anyone quote me or send me an extract from 16th edition or OSG that covers this aspect.

Cheers

 

[Spark123]

Within the permitted routes the cable does not require additional protection, iirc capping is only really for the plasterer anyhow.

http://www.niceic.org.uk/downloads/C5-43.pdf
http://www.niceic.org.uk/downloads/concealedcables.pdf
http://www.iee.org/Publish/WireRegs...les_concealed_in_thin_walls_or_partitions.pdf
http://www.tlc-direct.co.uk/Book/4.4.1.htm

 

[JohnD]

Have you suggested a route that he doesn't like?

Does your preferred route go straight (horizontally or vertically) between fittings, or is it diagonal?

 

[bondy]

guys, is he referring to the 1/3 and 1/6 rule vertical and horizontal for depth of chase in a wall "skin".

 

[JohnD]

what does "the cable has to be capped. i.e. vertical and horizontal from the fittings and within 15mm of the room edge." mean then?

 

[pcboffinuk]

Nijinski001,

I think bondy is right. Sounds like your leckie is confusing regs.

Providing the cable is within the zones you mention (horizontal/vertical from fittings or within 150mm of the TOP edge or the angle formed by two walls then no protection is required.

(Page 53 of the OSG)

If the cable is buried deeper than 50mm from any surface then it also doesn't need protection, wherever it runs.

Otherwise it does need protection, generally by means of an earthed metal conduit, although cable with an earthed metal sheath (such as mineral insulated cable), or an insulated concentric cable are other options.

Your Leckie may be meaning the 50mm depth mentioned above - the only thing that sets a maximum depth allowed for chasing is the building regulations relating to structure, which stipulates that


'vertical chases should not be deeper than one-third of the wall thickness or in cavity walls one-third of the thickness of the leaf'

and


'horizontal chases should not be deeper than one-sixth of the thickness of the leaf or all'


(page 118 of the Electricians guide to the Building Regulations)

Hope that helps

Gavin

 

[JohnD]

...a stipulated depth of chasing inside the zones or the cable has to be capped. i.e. vertical and horizontal from the fittings and within 15mm of the room edge.

I don't find the OP wording clear (especially about capping and "i.e."), but the electrician appears to have said:

Either chased deep
or
vertical or horizontal or near edges (actually 150mm)

So I don't understand what the electrician said that was wrong.

 

[JohnD]

duplicate, sorry

 

[Job_n_knock]

I take it that you are meant to do the chases and he wants them deep and you dont ?