DIY Hack Needed: Running cat6 in an insulated wall

[lykaon78]

I need to drop a cat6 cable from my attic to a junction box 6-8 feet below the attic in order to install a wireless access point to fix a dead spot in my home. It is an external wall with fiberglass insulation.

Is there a trick to get the cable to drop in the crowded space with insulation?

I thought about using some type of stick but because of the pitch of the roof I only have 2-4 feet of vertical clearance above the spot where I'm trying to drop the wire.

 

[boomerang]

Not a stick, but a fish tape or fish sticks. A fish tape is flexible, will get the job done and it's less expensive than fish sticks.

From above, you should have a clear view of the top plate of that wall. You'll want to drill a hole that is as close to the edge of that top plate as you can get that is obviously biased towards the interior of the house. Drill a large hole. I would use around a 1" spade bit minimum. Drill only as deep as necessary to go through the top plate then stop. A 1" hole should give you enough room to look in that hole and is more than enough room for a fish tape as well as your cabling. The idea is to run the fish tape down between the drywall and the insulation. You'll want to wrap the end of the fish tape with electrical tape to eliminate as best as is possible it snagging on the insulation.

Hopefully it's bat insulation with a paper facing. Hopefully there is no blocking in that stud cavity which you should be able to determine beforehand with a stud finder. I would put in the opening for the low voltage old work box prior to running the fish tape but leave the install of that box until you have your CAT cable in place.

That's how I'd do it as a homeowner that is not an electrician and that is also not interested in spending a lot for tools and equipment I'll probably only use once.

 

[nboy22]

I got lucky with mine and ran cables with a fish tape in a couple insulated walls. I drilled a hole as close as I could to the side of the wall where the drywall is (up at the headboard), and then my insulation was the type with a brown paper front/sheathing. I managed to get the fish tape head (which was like a wedge) in between the paper and the drywall. It slid down so easily.

In a previous attempt on a different house I tried to use the fiberglass rods with a piercing head and it just didn't work out. I couldn't push through all the insulation well enough to get down to where the outlet box was going to be. Perhaps if I had known about the in between the paper/drywall trick, it would have worked out for me in that house.

I suppose another option would be to drop the cable down in an uninsulated interior wall and then run it to the outlet under the baseboards. I actually ran the majority of the cat6 and speaker cables in my house under all the baseboards and door frame trim boards. It was a big project, but it worked out with some patience.

 

[lykaon78]

Before today I'd never heard of fish tape but I'll give it a shot. Thanks for taking the time to respond.

 

[lykaon78]

Is it possible there is 3-4, 2x4s at the junction of the ceiling joists and the exterior wall?

I'm balls deep in the wood with my spade bit and I'm not through wood.

 

[Greenman]

Is it possible there is 3-4, 2x4s at the junction of the ceiling joists and the exterior wall?

I'm balls deep in the wood with my spade bit and I'm not through wood.

Should be 3" thick of lumber at the top of the wall. Depending on which way the joists run, there could be another 1 1/2 of backing. You could be drilling right into the top of a stud as well, though doing that without hitting a nail would be a wild stroke of bad luck.

 

[Red Squirrel]

I try to avoid as best as I can running wire on outside walls. The issue is that it involves messing with the vapour barrier and puncturing it and it can be tough to get it to seal properly after. If you have a hole in it it will cause a draft and heat loss and possibly frost which will eventually lead to mold.

Is there a closet nearby, you could drop it down the closet ceiling. Fixing the vapour barrier at that point will be easier as you'll be able to visually see it then just tape up around the cable going through. For stuff like that I personally like to stick a small section of conduit, I caulk it in place then use plastic bags to fill the conduit once the wire is passed through. I have a few wires going in my attic for some sensors and an antenna and that's what I did and it seals pretty well.