routing non electrical cables

jmwhooper · Posted: Fri Dec 09, 2005 3:16 pm Post Subject: routing non electrical cables

Hi, I'm in the process of putting a plan together to run wiring around the house for a pc network, multiroom audio and video. The cables will be Cat5e, RG6 and speaker cables. Is there anything specific I need to be aware of for running these between walls (hollow plasterboard dividing walls), under floors etc.

Should conduit be used, if so do the same rules apply about capacity of conduit and number of wires. Is it better to use mulitple smaller diameter conduits or fewer larger diameter conduits, I'll be running maybe 20 wires from the main hub?

If I need to run wires across joists at a right angle is there a limt on the size or number of holes that can be drilled in the joist to feed wires through.

delmel · Posted: Fri Dec 09, 2005 6:43 pm Post Subject:

its never a good idea to try and cram a conduit full, leave yourself as much space as you can and ensure you do not bring into termination point where there are mains cables present. Although difficult and not always poss run them as far away from any mains cable as possable and i would suggest using screened cable.

ltfc · Posted: Fri Dec 09, 2005 7:16 pm Post Subject:

Holes in joists must greater than 50mm from the top of the joist and greater than 50mm from the bottom of the joist, Holes diameter should be less than .25 times joist depth and holes should be at least 3 diameters apart.

smokeyJoe · Posted: Fri Dec 09, 2005 8:18 pm Post Subject:

On drilling joists, remember:
A loaded joist will bend slightly, the top edge gets shorter as it's under compression while the bottom edge gets longer as it's under tension. The mid point stays the same length & so it's under no stress, this is called the neutral axis & is the best place to drill a hole as the joist is weakened less. Cables in the centre of a joist are usually deep enough not to get nailed.

jmwhooper · Posted: Tue Jan 03, 2006 1:59 pm Post Subject:

Another question, could i use another type of tubing for these cables, they are non electrical, i.e. speaker and tv ariel. Something like plumbing or guttering tubes.

If not does anyone know where to get some 2-3 inch electrical conduit, the stuff I've found in only about 1 inch!

JohnD · Posted: Tue Jan 03, 2006 2:32 pm Post Subject:

If you are sure you want to put them all inside one thing, what you may like is called ducting, not conduit.. Square or oblong section, not round. Available in steel or plastic. It is generaly used when attachd to walls, not under domestic flooring. The round or oval plastic conduit is very handy betwen joists, though.

You can also get a neat profiled thing like skirting that has cable channels inside.

breezer · Posted: Tue Jan 03, 2006 7:14 pm Post Subject:

JohnD wrote:

If you are sure you want to put them all inside one thing, what you may like is called ducting, not conduit.. Square or oblong section, not round.

AKA trunking

other suppliers are also available

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JohnD · Posted: Tue Jan 03, 2006 7:41 pm Post Subject:

You're right, trunking was what i was thinking of.

ban-all-sheds · Posted: Wed Jan 04, 2006 1:53 am Post Subject:

You won't forget to read what the Building Regulations have to say about "telephone wiring or extra-low voltage wiring for the purposes of communications, information technology, signalling, control and similar purposes", will you....

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jmwhooper · Posted: Thu Jan 12, 2006 7:26 pm Post Subject:

I found info that says no building notice is required for : "telephone wiring or extra-low voltage wiring for the purposes of communications, information technology, signalling, control and similar purposes, where the wiring is not in a special location;"

There is an ammedment to Schedule 2A "Installation of fixed low or extra-low voltage electrical installations will require a person registered....." but will speaker cables, video cables, CAT 6 and Coaxial cables fall under low voltage?

Unless I'm missing something then I think I'm ok to install these types of wires, and to put an extension on a telephone cable.

Any thoughts?

jmwhooper · Posted: Thu Jan 12, 2006 8:49 pm Post Subject:

breezer wrote:

JohnD wrote:

If you are sure you want to put them all inside one thing, what you may like is called ducting, not conduit.. Square or oblong section, not round.

AKA trunking

other suppliers are also available

What about something like this under the floors, lots of room for wires, nice and tidy and easy to run new (non mains electrical) wires through in the future

EDITED URL ABOVE

JohnD · Posted: Thu Jan 12, 2006 8:56 pm Post Subject:

That link didn't work, though it looked OK. I can't put it in as a URL wither, have to copy and paste it. Otherwise it goes to dgm2.com Who are they?

You meant the ducting used for fans and tumble driers?

jmwhooper · Posted: Fri Jan 13, 2006 2:15 pm Post Subject:

WRT to the building regulations, I spoke with the planning dept at my local council and they said I don't need to notify them or have the work inspected.

So with that I'll be running the cables this weekend.

Any tips for passing between a cavity wall space and getting past the horizontal noggins when running from the above room?