[Yoyoson]

Disclaimer: I'm a recently new homeowner so I may not possess the proper vocabulary. I also expect that my decisions in going about things are way less than ideal. In short, do not assume that I know what I am talking about!

Our living room was designed to mount the TV above the fireplace, but the wife and I are averse to that placement. Unfortunately the only coax cable outlet is above the fireplace, so in preparation for painting I am trying to put in a new one.

My plan was to use a remodel box with ears and mount it to the drywall. The new outlet spot is about 10-feet over and 4 feet above the basement furnace room where all the coax connects to in the house. All I had to do was run it down a floor and then over, because that room can "see" the "crawlspace" between floors.

After cutting the hole for the remodel box, I realized that I'll have to drill through a floor joist in the wall to get to the crawlspace.

I cut out enough drywall and removed the insulation from my wall to fit my whole drill in there, but I can only get about 3 inches deep in before I start to hit something that my drill bit cannot penetrate. At this point the drill starts to wobble in small circles at high speed.

My question: What could possibly be below the floor joist? And what should I do next?

Please let me know if I can explain further, and thank you for reading this!

 

[jarheadoo7]

is the I beam that is holding up your house under that joist?

 

[Wildie]

I assume from what I have read that you are working on an outside wall. (insulation)

An outside wall will have a rim joist and sill plate below it.

I have a hunch that you have drilled down through the rim joist and sill plate and have run into the concrete foundation.

Any time that I have been faced with this situation I have been able to drill at an angle from below. To do this its very important to know exactly where to drill.
The easiest way to do this is to drive a 3" finishing nail down through the floor as a reference marker. Then figure out where you need to drill up.

Extreme care must be taken when you drill from below as there is very real danger of causing damage if you drill in the wrong place and at the wrong angle.

 

[Jim Port]

Move over an inch or two and try to drill another hole. You may have hit a nail.

 

[joed]

You don't actually need a box for COAX cable. You can install low voltage ring if you wish. It will have the holes to mount a face plate.

 

[Yoyoson]

Thanks for all the quick responses!

is the I beam that is holding up your house under that joist?

I'm not sure how to tell. As Wildie correctly pointed out, the wall I'm working in is an outside wall, and it's not near any of the center lines of the house, so I'm going to guess that it's not that.

You don't actually need a box for COAX cable. You can install low voltage ring if you wish. It will have the holes to mount a face plate.

Cool. I don't actually have a box, it's kind of like a box with the back cut off of it, and with ears. I think it's also considered a low voltage-something.

Move over an inch or two and try to drill another hole. You may have hit a nail.

This I will have to try immediately!

I assume from what I have read that you are working on an outside wall. (insulation)

You are absolutely correct.

An outside wall will have a rim joist and sill plate below it.

I have a hunch that you have drilled down through the rim joist and sill plate and have run into the concrete foundation.

Something I should've pointed out before is that what I called my "basement" is actually the ground floor, and it's completely above ground. The outlet I'm trying to install is located on the Main floor, one floor above ground level.

During the purchase inspection, the guy pointed out that one of the walls of my garage is concrete, and I recall thinking that this was part of the foundation. Does this make any sense? Can a townhouse's foundation ever extend 8-9 feet above ground level?

Any time that I have been faced with this situation I have been able to drill at an angle from below. To do this its very important to know exactly where to drill.
The easiest way to do this is to drive a 3" finishing nail down through the floor as a reference marker. Then figure out where you need to drill up.

Extreme care must be taken when you drill from below as there is very real danger of causing damage if you drill in the wrong place and at the wrong angle.

If this is the approach I'll need to take, I may be in trouble because the "crawlspace" between the two floors is actually two short for me to get in there. I think it's maybe 1.5-2 feet high. This means I'll have to drive the finishing nail down through the floor and then start opening up sections of drywalled ceiling to locate the pointy end of it! If I've actually hit foundation then I'm probably going to give up at this point and call in a professional. Or else I'll get some cable that's easy to conceal.

 

[Yoyoson]

Move over an inch or two and try to drill another hole. You may have hit a nail.

This I will have to try immediately!

Success! I tried another spot an inch away, and it hit some kind of obstacle at about the same depth. Then I tried a third spot about 6 inches away and this time it went through. According to the fish tape, I can get about 16 inches down before I hit something else. I'm assuming that's the next set of joists below these.

Tomorrow I go to Home Depot, get myself a spade bit and widen it a bit so I can fit my cables in there and also direct the angle of the fish tape a bit more.

 

[Yoyoson]

Well, I managed to punch through to the other side. If I stick a flashlight on top of the hole, I can see the light from inside the furnace room.

It took a while though, probably on the other of 2-2.5 hours. The spade bit had to punch through some kind of particle board, which was sandwiched between two joists. I measured the depth of my hole at just over 3.5 inches.

Now the fishing begins, and next week, I get to patch up the giant mess I've made.

Thanks for the tips and guidance!