Help with fishing wire through external wall

[amaheshw]

Hello all,

I'm trying to wire and mount my two rear speakers. What I want to do is fish the wires down from the speaker location inside the wall to underneath the crawlspace and back up to where my receiver is located.

The problem is that one wall is an exterior wall that contains fire blocks and insulation. I was thinking about cutting a good-sized hole in the drywall and buying a long flexible drill bit. My plan was to stick it down the hole in the wall until it hits the floor and make a hole that would go into the crawlspace. Then I would just fish the wire back up.

My questions are:
1. What do I do about the fire block? Do I just cut the drywall where the fireblock is located and notch it?
2. Is it ok to pass the wire through the insulation or should I just run it alongside the stud?
3. Is this a realistic plan at all? And what other things should I be aware of? I love DIY projects and I love to learn this stuff. But I just want to make sure I'm not way over my head by checking with you experts!

Thanks for any guidance you guys can offer!

-Raj

 

[bcycle]

Raj

You can use a flexible drill bit to deal with both the floor and the fireblock. It does require some skill drilling the holes and fishing the wire. The bigger the hole the easier the fishing. (I use a 3/4). The hole in the sheetrock shouldn't have to be bigger than an inch or so using a flexible drill bit.

Other choice is to cut a hole in the sheetrock at the fireblock and floor with a hole saw big enough to get your standard drill in there to drill your holes. You can hand fish the wire through and patch the holes w/ joint compound using this method http://www.naturalhandyman.com/iip/infdrywall/inflargepatch.shtm. I normally do this, it's direct and if you're "mudding" techniques are pretty good, works very nicely.

Yes, you can run speaker wire through insulation; not a fire hazard. It may violate your building codes though.

Best,

Greg

 

[amaheshw]

Hi Greg,

Thanks for your response!

One question--you said the flexible drill bit requires skill drilling the holes and fishing. Could you expound a bit on what skills you are referring to. As far as fishing the cable, I was hoping that once the bit goes through into the crawlspace, I would just be able to attach the cable to the bit (from the crawlspace) and pull it back up. Or would the fishing of the cable have to be a separate step?

Right now, I'm leaning towards your second suggestion of cutting a hole in the drywall!

Raj

 

[majorloser]

Labor Saving Tools

Check out this website: http://www.lsdinc.com/

They sell the tools and show you how to use them

You can find info on the flexible bits and the directional guide tool.

 

[RLA]

Good luck with those flex bits I have a few laying around collecting dust.
They will work in some retro installations but if you have a high insulation R value rating in your exterior wall and you can’t get the angle and tracking correct for the bit you will get frustrated. It may be easier and more cost effective to notch out the dry wall at the fire block and patch the drywall. If you are installing in-walls this is a mute point because the hole you create for the speaker will provide drilling access for the pre-wire

 

[Johnd]

Yeah...fire block, insulation, fire hazard, code concerns. Just open it up as bcycle showed and then patch. Drilling blind can cause you to drill electrical wires, thermostat wires, etc. (unless you have an ir camera). Opening the cavity up insures a professional, safe installation, whilst not losing R-value on the disrupted insulation. Also, be sure to use ic rated wire. Cheers.

 

[amaheshw]

That's brings up another question. I have an electrical outlet at the next "stud cavity" which means obviously that electrical wires are nearby. What's a good rule of thumb in terms of distance to stay away from the wires? There is really only one place on that wall that I can put the speaker so moving it somewhere else is not an option. Are there any techniques to use so that the speaker cable and the electrical wire can peacefully coexist? And how the heck would I even know exactly where the electrical wire is without opening up that part of the wall too?

Thanks,
Raj

 

[Johnd]

1. One foot separation minimum between speaker and electrical wires.
2. Probes and toners are the preferred tools of the trade.