Romex useage

[nizak]

Does anyone here have a value that works out fairly consistently for romex useage in new construction? 14/2 for lighting and general purpose receps, 12-2 where required, and 14/3 for smokes and 3and 4way switching? Thanks.

 

[danickstr]

that sounds good to me. I don't really see the need for a lot of 12-2 rec. wiring, although there are guys who will disagree with me. Any two typical space heaters will overload both a 15 and 20 amp circuit, so what is the point of 12 gauge?

 

[ceb58]

Does anyone here have a value that works out fairly consistently for romex useage in new construction? 14/2 for lighting and general purpose receps, 12-2 where required, and 14/3 for smokes and 3and 4way switching? Thanks.

1000ft 14-2 per 1000 sq ft 500ft 12-2 per 1500 sq ft 500ft 14-3 per 1500 sq ft
This is a SWAG method but it get you real close unless there is something really crazy.

 

[roger]

and 14/3 for smokes and 3and 4way switching? Thanks.

What do you mean by this part of your question? If those devices are part of a 20 amp circuit they will have to be # 12, the same as the rest of the particular branch circuit conductors are.

Roger

 

[jumper]

What do you mean by this part of your question? If those devices are part of a 20 amp circuit they will have to be # 12, the same as the rest of the particular branch circuit conductors are.

Roger

OP said: 14/2 for lighting. I believe he is using 15 amp circuits for lights.

 

[roger]

OP said: 14/2 for lighting. I believe he is using 15 amp circuits for lights.

And I think you are right, I just wasn't absolutely sure that was what the OP meant.

Roger

 

[mivey]

...what is the point of 12 gauge?

600 additional VA per circuit, better performance on longer runs, sturdier wire.

The issue I have with #12 at times is I sometimes run into box fill issues with some switching setups, otherwise I do not use it except on a dedicated circuit with smaller known loads (like some lighting circuts, etc). I'm not a fan of 15 amp general use receptacles.

 

[jmellc]

I always use 14 for lights. I made the mistake once of using 12, since all existing lighting was done in 12. 12 crowds a box quickly & even when in limits, makes getting switches lined up a pain. Customer wants a dimmer, have to pack wire in with a hammer handle.

I use 12 for kitchen & bath ckts, as required. Sometimes for other recep ckts, like a workshop with lots of tools. If I kow things will be redone a lot, I use deep metal boxes with RS covers, allows more space to tap for a future something.

I have seen a space heater overload a 15 amp ckt by itself, a few of the larger ones. If I know space heaters will be used, I go to 12 for sure.

Sometimes I put 2 br's together on 12 instead of separate on 14. I play by ear, see how crowded panel is, how much load may be used, what I have on the truck, whether yellow or white cable is more appealing that day.......

 

[LarryFine]

I always use 14 for lights.

Agreed (unless the load needs 20a).

I use 12 for kitchen & bath ckts, as required.

Agreed.

If I know space heaters will be used, I go to 12 for sure.

Agreed.

Sometimes I put 2 br's together on 12 instead of separate on 14.

Disagree a bit. One 20a circuit will hold a large load that no number of 15a circuits will.

My default for GP receptacle circuits is 20a unless there's a reason to use a 15a circuit.