I'd like to run new cabling for data, voice and tv but I'm having a hard time figuring out how to get some of the wires up to the attic for the 2nd floor and would like some advice.

I've run cables, wire and conduit before but I've hit a wall (pun intended) and can't figure out what to do.

I was planning on using Cat6 for data and phone but might need to go with Cat5e for the thinner diameter. TV will be RG6 quad shielded. All together over 20 cables.

I could only find one section of interior wall that has a clean run from the basement to the attic but I still have to do some investigating. It's a 2x4 framed wall that may be be load bearing as all the joists run perpendicular to it but I can't remember if any framing members connect directly to the roof. I think I only have 1, maybe 1 1/2 stud bays I can use to run wires the whole way.

Here are the options I can think of:

Option 1 Drill holes with flexible drill bit

Using a 1" diameter flexible drill bit I can make 3 holes all the way up from the basement to the attic through all the sole plates, top plates and fire blocks.


  1. Do I need to fire block every penetration or just the top in the attic and bottom in the basement? What fire block material is good to plug around the cables at the end of the conduit?
  2. Is there any problem doing this with so many cables without conduit?

Option 2 Drill holes with forstner bit

Instead of using a flexible drill bit I can cut out the drywall by the top, bottom and middle of the wall near the fireblocking and drill the same 3 1" holes except I have more access for guiding the pull and fireblocking all penetrations.

Option 3 Use 1" or 1-1/4" Metal Conduit

I can run 3 1" (cat5e) or 3 1-1/4" (cat6) runs of conduit. I'd need to cut the drywall to drill the holes as I can't seem to find a flexible bit that is big enough for the conduit to fit. Thinking of using metal conduit because it has a smaller outside diameter.


  1. How do I get the conduit in the wall? If I cut the conduit in half (5') can I squeeze it in the hole and slide it up/down? I don't want to remove the fireblocking if possible and there isn't enough clearance in the basement or attic to feed the whole length.
  2. Does the conduit need to be attached to the studs? If I can only use 1 stud bay I only have two studs to nail the conduit to.
  3. What keeps the conduit from falling down? Even if I attach the conduit to the studs with straps it's going to be a straight run down. Are there some sort of end pieces that allow me to attach it to the top plate in the attic and bottom of 1st floor subfloor in the basement? Some sort of clamp and flange? I can't seem to find anything like that but I'm sure I've seen them installed.
  4. Along with Q3, is there some sort of bushing that can be attached to the end to protect the cables from rubbing against the edges of the conduit as it exits?

Option 4 Use 2" Conduit

If I could manage to do this everything would be so much easier as I can pull all the cables through 2".

As I understand it, if I cut a hole to accommodate a 2" pipe in a 2x4 framed wall I would need to reinforce the top plate with a steel plate. I've only seen them install on the side of the 2x4 (1.5" width side) which would be a problem since the walls are finished and I don't want to do that much damange to the drywall. In the attic I can attach it to the side but for the first floor is there something I can attach to the bottom? Maybe a 1/2" mending plate on either side of the 2" pipe?

Still same problem. How do I get the pipe in the wall?

Open to other options and suggestions and advice about how to run the cables up. Wifi isn't cutting it anymore and the ethernet over power options don't suit my needs either.

Here's a picture showing the walls in question. Keep in mind I'll only have 1 stud bay to run cables, maybe 1 1/2. There is a beam right under the wall in the basement but enough room above it to pass the cables around. I'm not sure of the exact height of the roof rafters over the wall in the attic but it's somewhere around the dimensions shown.

enter image description here

  • Have you considered the possibility of running a PVC conduit up the exterior of the building from the basement to the eves? Commented Feb 25, 2014 at 10:30
  • @shirlockhomes yeah but it would be harder and uglier. This wall gives me a straight run with no bends in the conduit. Commented Feb 25, 2014 at 11:17
  • 1
    I would have a PVC run and I would run an extra line for future use.
    – DMoore
    Commented Feb 25, 2014 at 18:40
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    You can get different sizes of PVC and you can run 2-3 lines in one run. It seems no matter what you will have to open a couple walls but might not be as bad as you think. If you have a rigid line then you can open up one wall on second floor - to drill to attic and first and then drill up to first from basement. Meaning just two small patches on same wall.
    – DMoore
    Commented Feb 25, 2014 at 19:04
  • 2
    As far as I know, unless something changed recently, there is no NEC code requirement for data or CATV cables to be in conduit in residential structures. Commented Feb 25, 2014 at 21:23

4 Answers 4


A professional would probably remove some drywall, install continuous conduit from end to end, and restore the drywall. It is a bit more disruptive, but not really harder than doing it with flexible bits and trickery.

  • Any advice on how I might get the conduit in? From below there's only a few inches of clearance. In the attic there's more but it's hard to get up there and I don't remember offhand. Maybe 3-4', five if I'm lucky. I've run conduit before but never in a situation like this. Commented Feb 25, 2014 at 3:46
  • 1
    You can use the flexible conduit, and clamp it to something in your attic (a piece of 2x4 that spans some joists would be fine) to keep it from falling down the wall. This is much easier to run in tight spaces, but you'll need to use more of them because they have a smaller diameter than the pvc.
    – BMitch
    Commented Feb 25, 2014 at 14:36
  • @Bmitch I was looking at Carlon raceway. Not too much more than EMT and solves a lot of problems. Plus it's orange and who doesn't like orange? :) Still looking into it. ID is just a little smaller than EMT which is throwing me off. Kinda leaning more towards EMT to get the shielding and protection since it's not to far from the AC handler and other electrical. If I cut the conduit to about 4.5' I should be able to feed it down from the attic in pieces and then couple it after it's all in place so I don't have to make the holes too big to accommodate the couplings. Commented Feb 25, 2014 at 19:10

After thinking about a little more I think I figured out how I can run the 1-1/4" conduit without doing too much damage. I'm going to go with EMT. 1-1/4" requires a hole that is less than 50% of the top plate so I don't need to worry about reinforcement. Still have to figure out the best spacing within the bay.

I'll start by removing small sections of drywall where I need to drill penetrations through the framing (including above the fireblocking.) I'll start the holes for the conduit up in the attic and cut the 10' lengths of conduit into sizes that I insert into the walls from the attic. Should be close to 5'. I'll insert three sections at a time, one in each hole and have someone on the floor below catch them in case the fireblocking is lower than the length of the conduit.

I'll drill each vertical obstruction one at a time starting from the top. That way I can mark where the conduit hits so I make sure all the holes line up. I'll do this until I get the first set of 3 conduits to the basement. At the basement I'll add an elbow to each conduit to make it easier to get around the beam. Will need to cut them down a little bit to fit. I can then secure the elbows to the underside of the floor.

Up in the first floor I'll cut off the conduit so that I can see the end from the holes I cut above the fire blocking. Here I'll add couplings to attach the next piece of conduit I'll send down.

That next piece should end above the sole plate of the second floor where I'll trim it to where I have the drywall cut, insert a coupling and send down the next section. This one I'll trim just above the fireblocking on the second floor and then install the final section.

Here's what the second floor will look like to give you an idea.

doh! Should have made the drywall a different color. Top hole is just above fireblock on second floor, bottom hole is just above floor of 2nd floor

To support the weight of the conduit and wire I'm going going to mount a 2x4 where the conduit comes up in the attic (if there isn't anything there) so I can attach clamps. Also found out about riser clamps which are used to support vertical pipe in situations like these. Will install these above the sole plate, fireblocking and top plate in attic.

I can use fire rated caulk or foam around all the penetrations since they're all open (oops need to make one more hole). Still looking for the best product to firestop the ends of the conduit. I saw something called fire putty that might work.

Not much drywall to repair and best of all it's in rooms I plan to repaint soon anyway.

Still need to find the right types of bushings to protect the cables from the edges of the conduit exit points.


If you have closets that are stacked on top of each other, it may be easier to just run the conduit inside the closets. That way you are only going through subfloors and ceilings, avoiding all structural members. If finished appearance is important, you could drywall over the pipe, too.

  • I was hoping I could run everything through a pantry but unfortunately things just don't line up. :( Commented Feb 25, 2014 at 14:56

In my current house I have run new wiring both in the walls and outside with conduit. If you have a clear run outside where the conduit will not be too obvious I would do it that way; especially on a multilevel run.

I have some wiring I am going to be running up a convenient inside wall to the second floor. I bought a cheap fiber-optic camera so I can look inside the wall. I have already run several cables down into the basement from the first floor using a 4ft flexible drill.

After 3 houses and many wiring projects, I have become quite good at patching and matching holes I make in the walls. Here's a trick: get one of those touch up rollers and use it to texture the paint after you apply it with a brush. Of course, that requires that you have been diligent about storing original paint.

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