Hole Drilling in top plate from attic

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

thapranksta

Home DIY Newbie
Joined
Oct 8, 2011
Messages
95
Reaction score
16
I am planning to fish some cat5e ethernet cables through the same wall cavity where coaxial cables are distributed throughout my home. The coaxials start on the first floor and run up to the attic. I found the hole where the coaxials exit but it is not large enough to accept more wires so I thought I would drill another hole or two to run the roughly 13 cables.

I successfully drilled a 3/8'' hole through a double top plate and fished a wire about a foot into the cavity. So I grabbed a spade bit and started drilling a 3/4'' hole in the exact same spot and probably made it through most, if not all, of the uppermost top plate when the battery on my drill died.

I started to think more about the spacing and the structural integrity. A view looking down on the hole I drilled is below. I am wondering if I have compromised the structural integrity at all with what I have done thus far and if I should stop drilling in the 3/4'' hole to the bottom left of the hole with all the wires. Those 2 holes are about an inch apart. I also want to know what is the maximum size hole I can drill and what distance apart? Would two or three 1'' holes be ok? Could I go with larger holes? Am I too close to the edge of the top plate? Thanks.

IMAG2736.jpg
 
The National Electrical Code requires holes containing non-metallic cable (often called Romex) or flexible metal-clad cable (the type you buy with the wires already in it) be set back 1-1/4 in. or more from the edge of a stud (Fig. A) to protect the wires from nails and screws. (The 1-1/4-in. screws and nails used to secure 1/2-in. drywall penetrate the studs about 3/4 in.) Most electricians keep their inspector happy by drilling 3/4-in. holes dead center on a 3-1/2 in. wide stud.

Spacing the holes 1-1/2" apart, centered, will be just fine.
 
Could I just patch the hole up with putty since I am sure it is less than an inch from the edge? Or maybe I just don't use that hole and leave it as is?
 
Don't worry about the structural integrity of the plate with the few holes you're drilling. Just use the spacing that Snoonyb recommended.
 
Plugging the isn't necessary, just remember not to place any electrical conductors through it.
 
Hut you do want to spray foam the holes (possibly fire rated caulk) to prevent heat loss and drafts.
 
Ok. Makes sense. I will make sure to fire caulk it up when finished. Any advice for fishing wire through a finished insulated wall although that time has not come quite yet?

Edit: I do have the advantage of having the bottom two feet of the wall open right now but the rest of the wall is covered in drywall.
 
Last edited:
If you spray foam in the hole next to the wires, you will never be able to remove the added wires, if it is the expanding type foam.
 
Elec. suppliers and some of the big boxes carry flexible fiberglass rods for the exact purpose.
 
We'd set several plaster ring per room, before drywall, or the data folks would install there own afterset rings.

And then the phone co. would staple just above the base, what a bunch of sissy's.
 
Well I got one of the holes completely drilled and went to fish the wire through and it would not go lower than the 2nd floor. It was hard for me to get my eyes in there but from my camera it looks like the spray foam was added in the cavity the coaxials were snaked through. Not sure if rods will help me or not. I may have to rethink my plans of having all cables centralized on 1st floor.
 
There will be a sil or bottom plate on the 2nd story wall and below the floor joists will be another set of double top plates for the 1st floor walls.

Unless the dwelling is of the age to have been ballon framed, in which case there may be fire blocking.
 
I was afraid that is the case. So if I were to go through with this, I would likely have to open up a wall on the 2nd floor AND the subfloor?
 
Yep, the best laid plans of mice and men.

How dedicated are you to this method, for this project?

Transitioning into the floor joist system is the least of the tasks, determining whats in there is another story.
 
I am pretty dedicated to this method to run the wire as I need to run wire to places on the first and second floor. I have also purchased a good bit of resources for it already. It seems if I don't do it here in existing wire channels I will still have to do it on some other wall where it may be more difficult. With that said, I am still open to better suggestions.

I made a pumpkin cut in the wall in a coat closet under a stairwell on the first floor - the place that I am running all the wire from. All the coaxials already originate from there and there is a GE smart connection center there but I do not plan to use it for my network wiring. I have room to cut higher up the wall but here is a picture of what's there when you look up in the first floor wall. I am able to stick my hand up and feel some type of "fuzzy" insulation.

IMAG2749.jpg
 
Then you'll define the enormity of the project by the number of locations.

Our contribution may be limited to the method of accessing, to reduce the difficulty of returning the dwelling to satisfactory habitability.
 
That's cool. That's the part I likely will need the most help with. :) I've cut the bottom of a wall open on the second floor and am able to access the bottom plate. I can see the route the wires are taking. I plan to drill two 1'' diameter holes centered at 1.5'' apart the same as the attic.

You could probably guess that I'm trying to avoid opening the subfloor as that will get super messy and I would have to remove carpet. The insulation in the top plate on the first floor looks like it is soft enough for wire to be snaked beside it but I guess I'll have to see.
 
Last edited:
In your case it's likely better for you to cut center to center of the studs.

I cut only the height of an angle cordless drill and a spade bit. Both the top and bottom cuts are chamfered so the the inner dimension is shorter than the surface dimension so that when you replace the, retained, piece, you butter both edges of the chamfer and screw the piece back in place, a little trowel work, prime and paint.

The problem with not folding the carpet back, finding the center of the floor joist and opening a narrow area, is that you don't know if the holes you drilled in the bottom plate will fall in the same joist bay, or if there is plumbing piping in the joist bay, or if there is elec. as well.

The alternative is a long bit, and hope.
 
I tried the long bit and hope approach. That didn't work. :( I went ahead and broke out the circular saw and opened up the subfloor. My wife is seething right now.

At any rate, I found out why the long bit approach didn't work. Apparently I am drilling directly down into an I-joist instead of a cavity. The coaxial cables actually come out the side of the top of the I-joist which looks very odd and then it exits at the bottom in a precut area. Pictures are attached. Now I'm wondering if I should try the same approach as far as exiting out of the corner of the top of the I-joist.

Top of I-joist (Entry from attic)
IMAG2773.jpg


Bottom of I-joist (Exit to 1st floor)
IMAG2772.jpg
 

Latest posts

Back
Top