Best way to drop cable between walls whose gaps are covered by plywood??

[Wizz]

Hello, I have to make a new RG6 run from the attic/crawlspace to a wall gap in our new home. Not only is the crawlspace tight (I have to go rafter to rafter, no walking boards up there), but it's also filled with 3 foot deep of polyfill type of loose insulation that I have to dig through to find the thin plywood floor. Well on top of all that the thin plywood flooring up there covers all the wall gaps, the only way I can identify a wall gap is to look for Romex going through a hole in the plywood where it proceeds to the elec outlets/gang box.

Anyone out there that had to deal with covered wall gaps in the attic what's the best way to drop the cable? Could I remove a sheet of plywood, or should I just drill a new hole next to the Romex in the attic near my chosen wall and look for it behind the electrical outlet/gang box?

Any advice is much appreciated as this is the hardest attic I've had to deal with. Thanks!

[houskamp]

just stay on the line of where the romex is (especialy if you find 2 in a row) and you'll be fine..

[rudeney]

First of all, be very careful drilling next to the electrical wiring as it's often stapled to the underside of the 2x4 wall header.

Traditional framing is that your walls will have vertical 2x4 studs spaced 16" apart, capped by two stacked horizontal 2x4's forming a "header". Then, 2x6 or 2x8 are set on edge as ceiling joists on top of those wall headers. If there is any plywood, that's usually installed on top of the joists. There may be insulation below the plywood flooring (between the joists) or above the plywood, or both.

Ultimately, you need access to the wall hear to drill into, and that is where you need to be careful as the electrical wire is often looped back and stapled to the bottom side of that. If you can, you need to pull up the plywood. If there's too much insulation, you could use a hole saw and drill an access hole into it, then use a long bit or bit extension to reach below it, past the height of the joists, and into the wall header.

[Wizz]

Thanks guys, that really helps. Yes, I believe there is a thin layer of insulation below the plywood, but it would be small enough to peel back easily. The plywood is very thin sheets so I'll see if I can remove a section in the location I need to make the drop and go from there.

Once I make the hole from the top side in the attic the next trick will be punching the hole for the wall plate in the same column on the bottom end...it would suck to be off a column or two when putting in the wall plate. Any tips/tricks to make sure I stay on line vertically when it comes time to install the wall plate on the bottom side??

Many thanks

[jhillestad]

Well worst case you could just pop it out through the ceiling at the corner or behind the nearest door then run it along the floorboard ... if you just dont wont to deal with all the drilling and hell....

[lwilbur]

A few times I have actually cut a hole in the top part of the wall in the area you are installing in and then drill a hole up into the attic then feed the line up into the attic. In my house this is actually easier because as you get toward the edges of the house there is only about a foot height of space to work in and then makes it a bear to try to drill a hole. Also, this way you know you are staying in the column you need to be in and you will see any electrical wires that may be stapled to the header. A small hole at the top of the wall is also a fairly easy drywall patch job and since its high up small repair flaws would be harder to notice.

[rudeney]

Once I make the hole from the top side in the attic the next trick will be punching the hole for the wall plate in the same column on the bottom end...it would suck to be off a column or two when putting in the wall plate. Any tips/tricks to make sure I stay on line vertically when it comes time to install the wall plate on the bottom side??

If you can measure distance from a known point, such as an outside wall, A/C vent, plumbing, etc., then you should be able able to hit it perfectly. If you can enlist a helper, then use glow rods (or a suitable substitute) to run down the hole and tap around inside the cavity. Your helper can then be in the room and locate it by sound and feeling.

[wallfishman]

you can measure, or you can have your kid bang on the ceiling with a broom stick while your up there and feel where your at. down below you cut your hole , stay the same height as the electric outlet. i always stay at least 6 inches from electric. then you can take a 1 foot piece of rg6 cable and strip the copper center conductor so its like 3 inches long. stick that thru the drywall ceiling directly above your hole.then find the piece of copper center conductor in the attic and thats where you drill. another trick is when measuring i use a piece of cable. i lay it on the floor and cut it to length from the wall to the hole. then take that cable to the attic and find the wall and u know exactly where to drill. for dropping down if its hollow i use a piece of chain and tie the center conductor of the cable to it and send it down the wall. in the room i have a flexible magnet thats like 18 inches long. stick it in the hole jiggle it around for a second then pull out the cable. that ways nice because you only need a 1 inch hole and can get away with 2 plastic anchors to secure the wallplate. if its exterior wall i use fishsticks. oh yeah and you have to remove a piece of that plywood so you have some room to work. otherwise you are going to end up drilling thru your ceiling

[joe diamond]

You need two holes in the top of the wall. One for the cable to go in....1/2 inch and one for you to look into...........also 1/2 inch. Locate where you want to put the new box and make a small (1 inch) hole there. Position a flash light to shine into the hole in the wall board.

Find the light by looking into the top holes..........When you see the light push the cable down into the wall.

FISH with a piece of wire until you have the cable..........pull it out & cut out the required shape for the "old work" box.

Good luck,

Joe

[Wizz]

Thanks guys!...if I have time I may start tomorrow. Thanks again for all the great tips.

[rudeney]

you can measure, or you can have your kid bang on the ceiling with a broom stick while your up there and feel where your at.

This also works with your wife, neighbor, neighbor's kid or even your neighbor's wife.

down below you cut your hole , stay the same height as the electric outlet. i always stay at least 6 inches from electric.

A stud finder will be handy here. You don't want to start cutting sheetrock out right on top of a stud and then have to repair it. Usually, your electrical outlets will be installed next to a stud. If you can find which side of the electrical box the stud is on, you can then figure you have 16" either side of that stud as hollow space. You can take the cover plate off the outlet and look for the stud next tot he box, or use something (preferably non-conductive) to probe the outside edges of the box to feel for the stud if you can't see it. Keep in mind that studs will be at the most 16" apart, but there could be studs in between, such as if there is an intersecting wall nearby, either in this room or behind the wall.

then you can take a 1 foot piece of rg6 cable and strip the copper center conductor so its like 3 inches long. stick that thru the drywall ceiling directly above your hole.then find the piece of copper center conductor in the attic and thats where you drill.

Yes, and that tiny little hole is easy to patch with a dot of sheetrock "mud" or thick paint. If your ceiling is textured, you might get away with not patching it at all.

another trick is when measuring i use a piece of cable. i lay it on the floor and cut it to length from the wall to the hole. then take that cable to the attic and find the wall and u know exactly where to drill.

Nice trick!

for dropping down if its hollow i use a piece of chain and tie the center conductor of the cable to it and send it down the wall. in the room i have a flexible magnet thats like 18 inches long. stick it in the hole jiggle it around for a second then pull out the cable. that ways nice because you only need a 1 inch hole and can get away with 2 plastic anchors to secure the wallplate.

I prefer to use an "old-work" box in mine. It just makes it neater (and I tend to be a bit anal-retentive). They also make low-voltage old-work boxes that have no back, which makes it easier to get the wire through, but it does make them harder to insulate (if that's a concern). I have large hands, but I am still able to reach through the cut-out for an old-work box and grab the cable. And if using old-work boxes, make sure you check to see if you need to cut a special pattern. Some fit a perfectly rectangular hole, but some need "ear" cut out. They usually come with templates (check for them at the store where they are sold).

if its exterior wall i use fishsticks.


Only on Fridays. :p

Seriously, "glow rods" or "fish sticks" or whatever you want to call them are the best thing if the wall is insulated.

oh yeah and you have to remove a piece of that plywood so you have some room to work. otherwise you are going to end up drilling thru your ceiling

But be careful with the plywood removed so you don't step through it! :eek2:

[Wizz]

Thanks. The attic is a nightmare...worst I've been in for wiring purposes and manouvering around. The plywood is not walkable...I would go straight through...I basically have to travel beam to beam holding onto the rafters watching carefully where I step while being crouched...if I stand up I'd get roofing nails to the cranium :blackeye: Not to mention they blew about 3ft deep of that poly-fill type insulation in there which covers up everything (water pipes, wire runs, etc)...it's like swimming in cotton and I have to literally dig it out to see where I'm stepping each step and to look for Romex runs, etc....PITA.

Good thing is the wall I want to drop to has 3 elec outlets on it so I'm just going to make a hole for the wallplate...put a light shining into that wall...then in the attic measure off a straight line from the 3 Romex feeds to that wall and drill a couple holes to look for the light...then make the drop. I'll be peeling up the thin sheet of plywood in that section if possible. But all of that blown in lose insulation that's 3ft deep is what will slow me down the most since I'll have to push it all out of the way to see or get to anything :bang