Getting Ethernet Cable Through Exterior Wall

Question

I am looking to run Ethernet cable outside my house. I have already found this question on running Ethernet cable outdoors, but it does not cover the best way to get the cable there.

Ideally, I would like a standard Ethernet jack on the inside of a standard exterior wall in an American home (drywall on the inside, presumably some thermal insulation in between, and clapboard siding outside, about 6 inches thick judging by the window). Regarding this I have a few questions:

1. What is the best way to do this that has minimal effect on insulation? I would prefer if this did not cause a stream of cold air to flood into the house.

2. Do I need to be concerned with various housing codes restricting how I am allowed to wire this?

3. Is there a safety concern with regards to the jack coming in contact with thermal insulation?

4. How do I minimize damage to the exterior clapboard? Is this even possible?

Answers to any of these questions are appreciated. Thank you!

Answer 1

Ethernet cabling is low voltage and installation has few requirements compared to regular electric (120V, 240V, etc.) wiring.

1 - What is the best way to do this that has minimal effect on insulation? I would prefer if this did not cause a stream of cold air to flood into the house.

I generally just drill a hole. I have a really long drill bit (I think 1/2" but not sure at the moment) for this purpose. Just make sure you know that it is a "safe" area - away from any electric wiring, plumbing, etc. and drill a hole. If you have any problem with air coming through, you can use foam (like Great Stuff) to fill the hole after you have the cabling done.

2 - Do I need to be concerned with various housing codes restricting how I am allowed to wire this?

There probably are some codes in some places. But generally I have not heard of many code issues with low-voltage wiring. It simply doesn't have the same safety issues that you have with regular A/C wiring.

3 - Is there a safety concern with regards to the jack coming in contact with thermal insulation?

Not that I know of. But there are 4 ways of doing this, and only one would have the jack in contact with insulation:

• Wall jack installed in box eliminator in insulated wall - then you have contact between insulation and jack.
• Surface mount jack (any wall) - cable goes through wall but jack is entirely inside the room.
• Wall jack installed in box eliminator in interior wall - i.e., run cable through a hole and then route it along the baseboard or through the ceiling or whatever, terminating with a jack installed in a non-insulated wall.
• Wall jack installed in a real box. The jack is in the box so not in contact with insulation.

I usually use a box eliminator and don't worry about the insulation, but I have done all of the above at times, depending on the specific situation. Of course, all except a surface mount jack will require cutting a good size rectangle in the inside wall, but it will be covered with the jack/wall plate. If you are working with paneling or something else stronger than drywall, surface mount may be easier.

4 - How do I minimize damage to the exterior clapboard? Is this even possible?

A small hole is really no big deal. The phone company & cable company do the same thing all the time. I find it is least obvious if the hole is a few inches from the ground, but sometimes it has to be higher up to match a reasonable location on the inside wall. The hole should not cause any problems. As noted by HazardousGlitch, the side you drill from will have the cleanest hole. So, all else being equal, drilling from the outside makes sense if you will be installing a jack (wall jack or surface mount) right where the cable comes. If you will be routing that cable to elsewhere then I would generally drill from the inside to keep the inside hole clean and so that you can position it very precisely (e.g., right above the baseboard). Most people tend to care more about the inside of the room than the outside of the house.

Answer 2

Best practice in my area (North America, Climate Region 5):

1. Drill a hole from the outside, obviously being careful to not hit anything critical within the wall or inside the home. If you have access, the best place is into a basement or crawl space where you can visually inspect any obstacles or dangers (water pipes, electrical lines, etc.). Bonus points if you can drill the hole angled up slightly (low point outside). Water doesn't like to run up hill.

2. On the outside wall, mount a quality (outdoor rated) box--preferably with a solid back. These can be easily sourced at any home improvement store. Drill a hole in the back to allow the wire to pass through, and holes to mount to the wall as needed. Ensure there is a quality gasket between the box and the wall or put silicone sealant (outdoor rated) on the top and sides (leaving the bottom exposed to allow any moisture to escape).

3. If possible, put a loop in the wire within the box. This will allow for any water that may condense on the wire to drip in the box instead of wick into the wall (in some climates, the differences in temperature from outside to inside can cause condensation). This is more common with exposed wire and isn't critical when inside a box.

4. Install the cover:

   • If you're terminating your LV wire in the box, use a quality (outdoor rated) weathertight cover and preferably use outdoor rated components wherever possible. A cheap plastic Ethernet jack will probably not last too long with outdoor use.

   • If you're running your cable into the ground, use an exterior rated plastic conduit from the box into the ground, this ensures that the cable is not exposed directly to the elements (especially the sun). Cheap PVC pipe is not good enough for this--be sure to use exterior-rated plastic pipe.

5. Be sure to use cable rated for exterior use. Regular (indoor) Ethernet cable will fail if you use it outdoors. It will probably be okay if you're terminating it in the box, but if you're going underground, get the right stuff for the job.

TL;DR
When talking about safety, low voltage is a bit of a misnomer. What most people mean is things like Ethernet, Telco and cable/satellite. These are very low risk and there are typically few, if any codes on entering the house. Landscape lighting on the other hand, is low voltage, but most landscape transformers are not rated for indoor use. Inspectors will usually flag installs that are not rated for indoor use. Solar panels are low voltage, but have lots of codes around their installation. But more to the point, "low voltage" can encompass things that can be dangerous--but Ethernet, Telco and cable are pretty risk free.