# How to fish wire through insulated wall



## joecaption (Nov 30, 2011)

I use one of these, it will drill the hole and allow you to attach the wire to the end of it so as you pull the drill back it also pulls the wire.
http://www.mygreenlee.com/GreenleeD...=showGreenleeProductTemplate&upc_number=38069
Lowes and Home Depot have them. But I'd measure how long it needs to be before buying one there, you may have to go to a real electrical supply to find one long enough.
I cut out the hole for the fixture the size of an old work box and feed the drill bit through that hole.


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## a_lost_shadow (Dec 18, 2011)

Here's how I'd do it. But I make no claims that it'll be the best way.

1) Use a stud finder to confirm that the stud bay is actually clear. I've found that most of the walls in my house have horizontal cross pieces an varying heights.
2) Cut a hole where you want the scone box.
3) Cut a small vertical hole below the first and above the bottom plate.
4) Drill the hole in the bottom plate (remember to keep it far enough back so you don't need nail plates 1.25" IIRC)
5) Repeat 1-4 for the switch if it's in an insulated wall (skipping 3 if not)
6) If both walls are insulated, run the wire between the two bottom plates. If only the scone wall, run the wire from the bottom plate all the way to the switch location.
7) Either send a fish between the holes in an insulated wall, or attach a weight to fishing line and send it down from the top hole. I've found you have to be very careful with some types of insulation. Otherwise the fish will go through the paper lining/vapor barrier and into the insulation.
8) Reel the fish and your wire in.


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## a_lost_shadow (Dec 18, 2011)

joecaption,
With insulated walls do you worry about staying on one side or another of the insulation, or do you just go through the insulation?


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## Julius793 (Dec 13, 2011)

joecaption said:


> I use one of these, it will drill the hole and allow you to attach the wire to the end of it so as you pull the drill back it also pulls the wire.
> http://www.mygreenlee.com/GreenleeDotCom/Products/main.shtml?greenlee_category_id=2&product_category=314&adodb_next_page=1&portalProcess_2=showGreenleeProductTemplate&upc_number=38069
> Lowes and Home Depot have them. But I'd measure how long it needs to be before buying one there, you may have to go to a real electrical supply to find one long enough.
> I cut out the hole for the fixture the size of an old work box and feed the drill bit through that hole.


Joe DON'T use that bit unless you have practice!


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## Hardway (Dec 28, 2011)

Julius793 said:


> Joe DON'T use that bit unless you have practice!


Julius why?


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## Hardway (Dec 28, 2011)

joecaption said:


> I use one of these, it will drill the hole and allow you to attach the wire to the end of it so as you pull the drill back it also pulls the wire.
> http://www.mygreenlee.com/GreenleeD...=showGreenleeProductTemplate&upc_number=38069
> Lowes and Home Depot have them. But I'd measure how long it needs to be before buying one there, you may have to go to a real electrical supply to find one long enough.
> I cut out the hole for the fixture the size of an old work box and feed the drill bit through that hole.


3/8" what size wire can be pulled thru that size hole?


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## Julius793 (Dec 13, 2011)

Hardway said:


> Julius why?


Well they tend to be hard to control in the beginning and can come out in unexpected places, such as the floor above, or the exterior of the house.


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## Thadius856 (Jun 2, 2011)

I've had those auger bits come back through the drywall or out the other side of the drywall. They're difficult to position unless you have the handle attachment or a leather glove. You should be able to tel if you're drilling through wood or not based on the sound of the bit. When in doubt, STOP! or you might just have a patch job. Worst case, you can drill through a fireblock if it came out the drywall right above/below it. :S

I find them difficult to use in insulated areas, as the sharp auger tip likes to rip through the paper of fiberglass bats and start taking fibers with them. I'd suggest a magnetic system for pulling wire past insulation, if you can get the holes made. Lube doesn't hurt either.


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## micromind (Mar 9, 2008)

To find the wall from under the house, drill a small hole a specific distance from the edge of the wall, directly under where you want the fixture. Shove a piece of small wire (like tie wire) about 3' through it, and let it dangle. It will be easy to find under the house. Once you've calculated the center of the wall, drill a hole from under the house. If you're using 14/2 NM cable, a 5/8" hole will do. 

If you can't get anything fished up or down the wall, get a piece of 1/4" all-thread. This is a continuously threaded rod that comes in 10' lengths. You'll have to cut it into pieces short enough to fit in the crawl space. Get some rod couplers. These are basically 1/4-20 nuts that are about an inch long. 

Tape the wire you want to fish up the wall to the end of one of the rods. Shove it up the hole you've drilled in the bottom plate of the wall. Work it around a bit, moving toward the side of the wall that the fixture goes on. It'll go easier if it's not going through the middle of the insulation. 

When the first rod is most of the way into the cavity, thread the second rod onto it using one of the rod couplings. 

Once it's high enough up the wall cavity, have another person look at the hole for the fixture box. You might have to wave the rod around a bit in order for them to see it. 

Rob


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## Hardway (Dec 28, 2011)

Julius793 said:


> Well they tend to be hard to control in the beginning and can come out in unexpected places, such as the floor above, or the exterior of the house.


 
IC, understood:thumbsup:


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## Hardway (Dec 28, 2011)

Thadius856 said:


> I've had those auger bits come back through the drywall or out the other side of the drywall. They're difficult to position unless you have the handle attachment or a leather glove. You should be able to tel if you're drilling through wood or not based on the sound of the bit. When in doubt, STOP! or you might just have a patch job. Worst case, you can drill through a fireblock if it came out the drywall right above/below it. :S
> 
> I find them difficult to use in insulated areas, as the sharp auger tip likes to rip through the paper of fiberglass bats and start taking fibers with them. I'd suggest a magnetic system for pulling wire past insulation, if you can get the holes made. Lube doesn't hurt either.


"I'd suggest a magnetic system for pulling wire"

please explan and source


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## rrolleston (Oct 17, 2011)

Those bits are terrible for use in insulated areas. They will ruin your insulation because the insulation just wraps around them and you end up with a baseball size of insulation wadded up on the end of the bit. I suggest locating the inside wall from below and running all your wire down below.


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## Stubbie (Jan 7, 2007)

Use a old steel tape like a Stanley, cut the lip off the end and then cut the tape to a point. Make sure it does not retract into the tape housing or try it with the lip still in place..Bore the hole from underneath into the wall cavity. A 7/8" hole works well. Cut the hole for the sconce and be freakin sure it is the right size hole. Measure the approx. vertical distance. Now feed the tape up thru the hole in the bottom plate ... it will go thru the insulation quite easily and if you can guide it so that it rides the inside of the drywall if will go thru the insulation like butter. Watch the tape when you reach the measured distance .. reach in the sconce hole with a hooked wire and grab the tape unless of course you can see it. Tie a pull string to the tape and pull it back.


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## Thadius856 (Jun 2, 2011)

The MagnePull comes to mind. Haven't used it, but it looks very useful. It might cost more than you'd want to spend for a single application.

A basic how to video with it: http://youtu.be/9movZLFc_Zk
A more advanced video for cavities with fiberglass insulation batts: http://youtu.be/3_2P3dM41eE

There's more on YouTube, and you could even make your own device like this.


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## Hardway (Dec 28, 2011)

Looks like it magic!


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## Hardway (Dec 28, 2011)

Looks like it magic!


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## plummen (Jan 10, 2010)

Hardway said:


> Julius why?


A semi unguided missile in untrained hands :laughing:
Think about what that bit could do if it snagged some romex inside the wall


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## plummen (Jan 10, 2010)

Doesnt anybody use a fish tape anymore? :laughing:


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## Hardway (Dec 28, 2011)

plummen said:


> A semi unguided missile in untrained hands :laughing:
> Think about what that bit could do if it snagged some romex inside the wall


I got all that, just making sure I don't miss any wisdom.


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## jimmy21 (Jul 2, 2008)

fiberglass glow rods. I also like drilling a 3/4 inch hole and then using the back side of one of those flex bits. They are stiff enough to just poke right through the insulation. #6 solid copper works well too.


Or just cut the wall open and patch it. Customers always refuse that option though


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## PaliBob (Jun 11, 2008)

Here are the fiberglass glow rods:
http://www.amazon.com/KLEIN-TOOLS-56102-Fiberglass-Glow/dp/B0026T7QE6

Then there is:
http://www.harborfreight.com/3-16-inch-x-33-ft-fiberglass-wire-running-kit-65326.html


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