Comments on: Floor cabling

Question: Floor cabling

cgs — Thu, 25 Oct 2007 08:21:07 -0800

How do I run a cable under my floor?

Let me be a little more precise: How do I run a string from one hole, under 12 feet of floor, and then fish it out of a second hole on the other side? Once I have the string, I can then pull heavier cord, then my cables, etc.

I've been considering everything from fishing poles, powerful magnets, to mice and cheese.

If it is impossible w/o pulling up the floorboards or turning them into swiss cheese, then I will admit defeat and buy those raceways mentioned in previous AskMeFi posts.

Thanks for your help!

By: aramaic

aramaic — Thu, 25 Oct 2007 08:24:43 -0800

What's under your floor? I mean, what's the structure made of?

By: zeoslap

zeoslap — Thu, 25 Oct 2007 08:26:10 -0800

Depends what is under the floor, if it's a concrete slab you are out of luck, if the joists are running perpendicular to the direction you are trying to go then again out of luck. If the joists are going parallel to where you want to go then you may be able to do it with a metal chain and a real strong magnet, or some of those bendy poles/fish tape you can get at Home Depot for just this purpose

By: zeoslap

zeoslap — Thu, 25 Oct 2007 08:27:42 -0800

Here are some tools that may help

By: enobeet

enobeet — Thu, 25 Oct 2007 08:27:44 -0800

Use an air compressor. Blow the air in one side, if there is no other place for the air to go, you can send a string to the other end. Progressively pull more secure cords through.

By: beagle

beagle — Thu, 25 Oct 2007 08:29:24 -0800

You need an electrician's snake. You can push this under the floor (assuming there are no barriers between the holes), then catch it at the other hole with another snake or just a coat hanger, and then pull your wire or string back from second hole to first.

By: GuyZero

GuyZero — Thu, 25 Oct 2007 08:40:27 -0800

What beagle said, though I have always called it "fish tape".

By: Leon

Leon — Thu, 25 Oct 2007 08:49:58 -0800

When I was doing this, I used 30 amp cable (the stuff you use for showers and cookers). It's stiff enough to get to the other end, but flexible enough that you can ram it down a hole behind the skirting board. Conduit can work for short runs, but doesn't bend.

But sometimes, there's no choice but to cut a trap or to get under there and pull the cable yourself. Small children are useful for this.

By: jquinby

jquinby — Thu, 25 Oct 2007 09:01:38 -0800

Thirding the fish-tape with the caveats as listed by zeoslap above. The fish-tape is also useful for other things, like dragging dryer-vent brushes through long stretches of ductwork.

By: noloveforned

noloveforned — Thu, 25 Oct 2007 09:51:50 -0800

what about using a 20' tape measure with a piece of string tied to it?

By: metric space

metric space — Thu, 25 Oct 2007 09:58:38 -0800

If the under-the-floor route doesn't work out and you have base and/or shoe molding over drywall, it's possible to run low-voltage wires behind the molding. You'll need to remove the it and possibly cut a channel in the wall. I had a contractor do this once when they had finished a room without properly installing all the wires that they should have. Whether it's worth the work in your situation is of course up to you.

By: cgs

cgs — Thu, 25 Oct 2007 10:57:43 -0800

holy crap.... that fish-tape is perfect! there is space under the floor, and the joists are running my way, so i'm good to go.

noloveforned- i'll try your way first... i hadn't thought at all about my tape measure.

thanks everyone!

By: ilumos

ilumos — Mon, 29 Oct 2007 16:48:17 -0800

Sometimes using the lid from a piece of square conduite can do the job, tape the cable to one end and bend the lid under the floor. It's rigid enough to pus most things out the way, and be able to be controlled as you push it through (unline solid core 30A cable) but bendy enough to go through.

http://www.networkcablingservices.co.uk/acatalog/standard_trunking.jpg

Also concider putting a "drawline" through as you place the cable, should you or someone else want to pull any other cables through. A bit of nylon string/rope will do it.