cable for communication audio video

I have dug a trench in the ground open right now to run a PVC conduit from the house to the front gate area in order to provide 120V power for a sliding gate motor.

Funny thing is, I don't think this is the first trench, because I kept running into previous wires along the same path, just shallower. My trench is about 20" so the conduit can sit below 18". Previous wires were just cables buried 4", 8", 10" etc...

I ran into multiple cables, a set of 18/2 wires which I think was probably used for an intercom system for guest to press and announce their arrival. I then ran into two other sets of 18/2 (could be 20/2) and I am pretty sure one set goes to the pedestrian gate electronic door strike (which has been replaced with regular key entry some time later but I can still see the wires tucked back in the door strike plate. I have no idea what the third set of /2 wires was for. On top of that there is a phone cable going from house to the gate but was cut off when it got close. So four sets of cables for whatever they needed back in 1992.

So that got me thinking, I may need some additional wiring in the future at the gate, may be for a security camera, may be a video door bell, I may need two way audio or video, I am not sure what I may need, and I think may be it's a good idea to lay down some generic cable into the trench before closing up the trench for whatever need I may have in the future?

What is the most versatile cable I can lay down for this purpose when the actual device(s) is not known at this time? Would a set of 18/5 be a good idea? How about a CAT6 cable? Just trying to think ahead (but not too much).

 

I would lay a second conduit and leave it empty.

 

I second the second conduit.
One for HV and the other for LV.

 

Yes I agree an empty conduit is the most versatile. I may do that.

The other thing is I have 18/2, 20/2, coaxial, cat5 cables left over for years...so I figure I can use these leftovers now. Now if I put in a 1/2" conduit now, and later on I need an 18/5 and a cat6, I can't possibly pull these cable through and the conduit when it's cable inside is more a sleeve and not a raceway right?

 

Until the conduit gets more filled, there's no reason you can't do multiple pulls over time. I usually feed some cheap twine through it as a pull cord, and when I pull the first cable, pull another pull cord with it for next time.

As things are getting more and more wireless, it's a lot less necessary than it was 10-20 years ago. But for a bit of extra money, I'd say the spare 1/2" or 3/4" conduit is well worthwhile.