Fiber vs STP vs UTP for underground conduit run to backyard office?

Question

We're building a standalone structure in the backyard that will be used for a backyard office. There's already a trench with a conduit for electrical and a 3/4" conduit for some sort of networking. The trick is figuring out which type of networking cable to run through that conduit.

I was originally planning on pulling fiber out there due to concerns about the proximity of the electrical conduit (they're right on top of each other). I was also recently reading about various shielded forms of ethernet cable and thinking that might be a better/easier choice? The run from the networking cabinet is about 80-100' in total, with about 30' of that inside and about 50' outside via the conduit.

Is fiber the obvious right choice here? Should I bother pulling it myself? I had one local company come out and quote me for pulling the fiber and the price was way higher than I expected. Another local company told me they could run Cat8 through the conduit, but after reading about how to ground the shielding on STP cables I'm not at all sure that's a good idea.

For code purposes I'm in King County in western Washington State.

Answer 1

Fiber is the obvious choice, for multiple reasons. If you choose not to do fiber, point-to-point wireless is likely the next logical option, given a short distance.

The biggest one is that fiber does not need lightning/surge suppression, since it does not conduct electricity. You also don't have to replace lighting/surge suppressors that don't survive a surge.

Most networking companies do come in rather high on doing fiber, but if you get pre-terminated cable suitable for wet locations (probably "indoor/outdoor" is your best bet) somewhat longer than you need it's not too hard to pull it yourself, especially if you get "reduced bend radius" fiber.

However, getting pre-terminated fiber through a 3/4" conduit may be a bit iffy, even with LC (small) connectors, since the connectors need to be protected for the pull and that adds some bulk. Look for a cable with a pulling eye in place, and verify with the vendor that it will work in 3/4" conduit.

Myself, I learned to do "old school" hand-polish terminations rather than pay a company a great deal more for a project, but that was a bit larger scale than one cable in the back yard. I paid for the equipment and supplies many times over .vs. the quoted price.

There are also "mechanical splice" connectors out there, but the tools to use them would probably have to be rentals to make any sense unless your local company is the only option and very high priced.

If the trench is open, drop in some larger conduit.

"Somewhat longer than you need" - just coil the excess neatly, and enjoy not coming up short, or not worrying about having to cut some off and re-terminate if you have a problem. It's called a "Moves, Adds and Changes" loop, and when you don't have one, you tend to regret it, eventually.