I’m not really, but have recently become one.
In logical preparation of the pre-drywall checklist in the new build, I contacted our local cable provider (Comcast) to run cable and internet before insulation and drywall. Three Comcast folks confirmed, yes! good idea, let’s schedule that install while the build is at the framed, pre-insulated stage. I thought it was a great idea as well, as I was well versed with the complex multi-directional framing which included dozens of joists throughout the home — and the limitations this particular design would introduce relative to where the cabling would ultimately run in a consolidated installed (second floor media closet).
Despite the confirmations, and after the first “installation visit” (with no installation), it turns out that Comcast will not install in a framed, ready for insulation and drywall home for either cable or internet for liability reasons (my experience is Comcast Seattle). The resulting conversations (about 6 hours in total over a 3 day span) came down to “when you have drywall, are moved in, and all of your furniture is there”, then they’ll install. Hmm, you say? Yes indeed, me as well.
Because we’ve been working so hard to build a beautiful custom home I like most, didn’t want dozens of cables running on the house exterior. In many cases where you want media, not all the rooms are conveniently located for a Comcast installer to run them from the street pole location. Additionally, there is no easy way to ‘fish’ cables from one room to another — they will always be blocked by a beam as in this case have them running both north and south, and east and west depending on the room.
Naturally that led to running the lines ourselves so here is what I learned as “the cable guy”:
R6 coaxial cable is the newest standard and the preferred quality is 18 RG6 Quad Shield CU CATV CM/CL2 Coaxial Cable — the Quad shield is a little more expensive than others, but is the best bet to minimize interference with other cables running in the house (we are also running shielded cat6 ethernet cable) and worth the little bit more extra cost. Note that the “CL2” or “CL3” rating on both coaxial and Ethernet indicate they are code approved to run inside the walls.
It is also worthy to note that if you have close neighbors, you could erroneously experience interference with their lines which is difficult for any cable provider to isolate as often it will come down to the quality of your cable line, not the provider’s signal.
TYPES OF COAXIAL CABLE
There are two types of coaxial cables; those with a center conductor made out of solid copper, and those with a center conductor that is steel with a thin skin of copper. Unless you have DirectTV, you do not need the solid copper (which also conducts electricity), which is how DirectTV works, and a requirement. Yikes! I’m all worked up about a cable running up the exterior and I personally would never (again) have a dish installed. (When I switched services years ago I was stuck with a cut cable at the box, and a dish on the roof). For a detailed layman’s explanation of cable, this is a great post.
For most other cable/internet providers (in the Pacific Northwest in any case), the coaxial cable only runs the digital signal from the city pole, no electricity.
IN WALL, IN DUCT RATINGS
In our case, we have both under floor radiant PEX heat, as well as ductless LG mini split A/C (which also is used for heat if needed as an inherent function of the unit). It is critical to know that your wires are rated for where they will be running. Most in wall cables will be rated CL2 or CL3 (your city inspector will pay attention to this rating and require its suitability). 
Given our scenario not having traditional ducting (if you do, you must pay attention to whether your cable (coax, Ethernet, speaker, etc.) is plenum rated — a special fire resistant shield that is designed to be in proximity of heat or air circulation spaces). Not running the appropriate cable for your application could spell expensive disaster. As I’ve gone through my Ethernet learning curve (non plenum spaces, suitable for ‘step’ installation), I thought it useful to provide a link that explains both plenum dangers, as well as a handy list of cable ratings and their applications. And the dramatic video is more fun to watch than reading about it.
INTERFERENCE
Interference can come from both the inside of the home, as well as any neighboring properties that also have various signals. In our case, we used to have a sporadic issue as our neighbor is less than 5′ away from where our internet line (and modem location) came into the home. All the shielded cables (I am positive we did not have ANY whatsoever) do help, but in-wall proximity to electric wires (12/2 romex, etc.) can also potentially interfere.
If you want to maximize holes that are already drilled into the framing, you’ll want to either run the coax 6″ or more away from the romex, or create a 90 degree intersection where the two meet only briefly. (And never have a bend less than 3″ or you may damage the cable causing interference or potential line failure anyway).
In this case, our romex runs horizontally through the interior wall studs to their ultimate light or outlet destination. 
A most brilliant post here gives fantastic easy to follow do and don’t tips for running coax.
Ultimately there were four options: 1) run the coax vertically in the wall studs with multiple horizontal cross over points, 2) run the coax in the ceiling with multiple cross over points, 3) drill new holes in the neighboring 16 on center ceiling bays, or 4) run the coax in the existing A/C insulated cabling run. **check with your city’s code on this, and with your HVAC folks**
Now, on with the wiring!
