Under floor cable trunking

Mark Ward

Active Member
Any recommendations for a cost effective solution here? When I lift the floor it's basically a void and dirt below so I want to protect the cables from damp & rodents. In additon the ability to re-cable without lifting the floor again will be a big bonus.

This is specifically for the run to the floor mounted PJ to the side wall where the rack will sit.

EDIT:- No sooner had I written this than an obvious solution came to me. It has to be the waste pipe type pipe you fit under a sink surely? Screw together sections and water tight too.

I've left the thread here to see what others would do.



My mate works for a certain water company, & he kindly half-inched me some water piping (the stuff used under roads) which is incredibly tough & would take a Rat with teeth the size of a tiger to chew through...
I got about 50ft for zero £££'s...although i did give him a crate of Millers for his trouble.....


Mark Ward

Active Member
water piping (the stuff used under roads) which is incredibly tough
Yes, that stuff would be great for some of the longer runs. Some of my runs will be over 10M. Will have to check the back of the van next time the water board are fixing a leak round here ;).

The White pipe I'm on about has a wider diameter I believe and would be perfect where I need to come up in the middle of the floor for the PJ. I wonder... would running a mains lead in the same pipe interfere with the 6M 5BNC to 5BNC cable I'm intending to run to the Barco?


Mike Swannick

1.5" (40mm) waste pipe is fairly cheap from a plumbers merchants, as are the connecters to join it all up.

You have two choices of pipe type:

1. Solvent weld - where the pipe and connecters are glued together to form a permenant connection

2. Push fit - where the component parts are held together by (more than adequate) friction. Push fit is cheaper than solvent weld.

When negotiating a 90' bend I would recommend a sweeping type bend made up of 2 45' bends with a short piece of pipe inbetween rather than a single bend or elbow (elbows turn more tightly than bends) to prevent snagging when pulling cables through.

Also thread your pulling line (moisture resistant 2/4mm nylon cord) as you build up the conduit with a total line length exceeding TWICE the conduit length so you can pull both ways without losing the end. If you use solvent weld don't glue your pulling line to the inside of the pipe!! Tie an object bigger than the bore of the pipe to each end of the line to prevent line loss.

If you think you might require a greater bore pipe, solvent weld comes in 2", 3" & 4" varieties too though you may have to hunt them down and pay through the nose when you find them. Pond supplies shop do these fittings in the above sizes. The 4" is also available in push fit as underground (terracotta colour) pipe.

As a price guide Wickes charged £1.00 per 40mm push fit fitting, my local plumbers did the same for about 55p. Use www.screwfix.com as a price guide to cost it all.

Can't help about the electrical interference question.

Sorry if you had considered some of this already.

Mark Ward

Active Member
Thanks for the tips Mike, This is only an issue with the PJ run, I'm guessing it will be a no-no to include a mains cable withing the same pipe but I'll wait for confirmation of this before I start running the pipes this weekend.

I'm intending to run pipes to every 7 speaker 2 sub position as well at to the PJ.

If I replace cables I was thinking the old cable would be an adequate pull-through chord but it won't hurt to run some nylon chord at the some time. For the speaker runs I really like Adzman's idea on the water pipe as there would be no joins or angles to worry about. I intend each pipe to come up through the carpet via a floor mounted flush junction box.

The main reason for all this is to make a change to active speakers as painless as possible at a later date.




I used waste pipe under my floor. I have a void under the floor into which I could crawl, and was expecting to have to cut and join the pipe numerous times, but it was amazingly bendy, and it all went in in one 3 meter length!

I ran some synthetic string through as well at the same time, in case I need to pull an additional cable through, rather than a replacement cable. It cost a massive £3.50 for a 3m length.


Hi Mark

A few years ago I used to use CableTalk 4 bi-wire, and changed my room layout which left me with several metres of both the L/R channels running together down a wall. After a few weeks of nagging by the wife I decided to tidy up the loose wire and used tie-wraps to secure the two cable together neatly along the skirting board. Several days later when listening to one of my favourite CD's I couldn't understand why the music sounded awful. I kept thinking that it was taking a long time for the system to 'warm-up' and lose it's 'muddy' sound. After a lot of head scratching and checking connections it dawned on me that maybe the 'tidied-up' speaker cable may be the culprit so I cut off the tie-wraps and separated the cable and 'viola' the muddyness vanished. So if I were in your position I would run separate trunking for mains, video and each of the sound channels, like you say you don't want to have to lift the floor again and plastic pipe isn't very expensive, although I would use proper electrical trunking.



Standard Member
'...I couldn't understand why the music sounded awful. I kept thinking that it was taking a
long time for the system to 'warm-up' and lose it's 'muddy' sound...'

I had a 'similar' experience with my cables. Before I moved house I had some Cable Talk
bi- wire connected between my Odyssey Stratos Power Amp, and a pair of KEF 104.2's. In my
new house, I replaced the cable with some far more expensive QED Silver Anniversary cable
and spent a long time neatening up the cables. Ever since I installed the new set up, the
sound always sounded muddy and flat . The amp takes 3 days before it begins to sound
right, so I left it for ages (you never switch it off by the way). Anyway, no joy until I
went here - http://www.tnt-audio.com/clinica/diycables.html

and built some of my own speaker cables. 1st using the CAT5 solution and then the more
'exotic' assemblies. The transformation in my system even with just the braided CAT5 was
remarkable and unmistakable. I kept all the previous cables and swapped them back over
just to double check. Quite unbelievable the difference it has made - IN MY OPINION that
is. The sites a pretty fascinating read also.

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