Renovation of a small storage room: electrical

[DaveC426913]

TL;DR Summary

Do I have to run new lines from the panel?

I'm going to blow out the walls of an existing storage 8'x6' room in the basement to make a bigger 11'x8' storage room. It won't be used a lot. but it'll need a ceiling light and a wall outlet or two.

It's on two outside walls, but it does have two adjoining rooms with electrical service (some of whch was put in professionally just last year. Still holes in the walls).

I'm comfortable doing light electrical work, but if I understand correctly, you're not really supposed to run new lines off existing ones, even in junction boxes. (I'm not worried about loading; only really need lights.)

But would it mean I have to run lines right from the box? (I would have a professional in to do that.)

Do I have other options?

 

[berkeman]

I'm going to blow out the walls of an existing storage 8'x6' room in the basement to make a bigger 11'x8' storage room. It won't be used a lot. but it'll need a ceiling light and a wall outlet or two.

You should ask your local city building department about this question. They can let you know if you need to pull a permit for this electrical work.

Also, are any of those walls load bearing? If so, you will need to pull a permit for that part of the work.

 

[DaveC426913]

You should ask your local city building department about this question. They can let you know if you need to pull a permit for this electrical work.

Thanks, but it's pretty minor.

Also, are any of those walls load bearing? If so, you will need to pull a permit for that part of the work.

Full disclsure: This was a wall built by the former owner to turn this space into a room for a student. Deplorable conditions. This was a section of the laundry room that he just put up a wall with a bit of scrap paneling. No light, no outlets. Bare cinder block. Def no load-bearing walls here. We've been using it as storage for boxes. It does a kindness to the house to remove this mess. I just want a storage space that doesn't look like trash.

 

[Averagesupernova]

I wouldn't hesitate to run a new circuit from the breaker panel if necessary. Depending on your locality it is quite possible you can add a single new circuit without pulling a permit.
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Couple of points: Watch for box fill limitations. This applies to all cases, but especially if you take power off of an existing circuit. You will kick yourself if you suddenly realize you can't squeeze everything back in by adding another cable to an already full box.
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This should give you some guidance.
https://www.ecmweb.com/content/article/20886012/box-fill-calculations
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If you tap into an existing circuit, keep in mind how heavily loaded the existing circuit already is. Rule of thumb is each outlet (outlet includes ceiling fixtures also, not just plug in receptacles) consumes 180 watts. So the limit on a 15 amp 120 volt circuit would be 8 outlets figuring with the 80% continuous rule. This is NOT a rule of the NEC. It's just good practice. Consider also getting left in complete darkness if all of your lights in the basement are on one circuit if a breaker trips. You will need to use GFCI receptacles in unfinished spaces. So if your floor is bare concrete you will need GFCI receptacles.
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Not sure on the latest concerning arc fault circuit breakers. I suspect just about any living space now requires them. Hope this helps. If you have any other questions I'll try to answer.
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Edit: One of the main things I wanted to mention and forgot. Do not tap off the laundry circuit. The circuit that runs your washing machine needs to stay just that. If you have a basement bathroom do not tap off of that circuit either.

 

[DaveC426913]

Well if I'm running a new line from the box I'm getting it done by a pro.

That wasn't really the question though. The question was: do I need to run a new line from the box?

 

[Averagesupernova]

The question was: do I need to run a new line from the box?

We can't possibly know that. I gave you some information to help you to make your own decision. If you can't make sense of that then you need to hire it done regardless of whether it would be a new circuit or not.

 

[DaveC426913]

We can't possibly know that.

Sorry. I am not 'splaining myself.

How can I provide light and wall outlets to a storage room without running a line back to the box?


I ran a lights and plug off an existing octagon in my old house, and some electrician pointed out you're not supposed to run a new line off like that from an octagon. But it was a pretty general, cryptic comment.

I wonder if all he meant was that, in general, it's best practice to run a line back to the box, because they way I had done is loading up an exisying circuit that may or may not be able to handle the increased load.

It's also possible all he meant was you're not supposed to double-purpose an octagon (as in diagram 2). That a split in a circuit should be in its own box (as in diagram 3).

 

[Averagesupernova]

and some electrician pointed out you're not supposed to run a new line off like that from an octagon.

That is not inherently true. Go by what was said in my previous post.
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It's not uncommon at all to run a cable out of a ceiling box on to feed the rest of the circuit. Just watch for exceeding the box fill limit.

 

[DaveC426913]

That is not inherently true. Go by what was said in my previous post.
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It's not uncommon at all to run a cable out of a ceiling box on to feed the rest of the circuit. Just watch for exceeding the box fill limit.

Thanks. I re-read that more carefully. Very helpful.

 

[Averagesupernova]

Thanks. I re-read that more carefully. Very helpful.

Let us know what you find and plan on doing.

 

[jack action]

It's also possible all he meant was you're not supposed to double-purpose an octagon (as in diagram 2).

The following link is written by a Canadian electrician and suggests just that: double-purpose an octagon. (Way more complicated than your diagram.)

https://www.electrical-online.com/wiring-a-circuit-how-to-run-two-lights-from-one-switch/

 

[Averagesupernova]

Yeah, what that link describes is not uncommon. I recall doing something like that with the last house I was involved with wiring. Nothing wrong with it. 3 conductor plus ground wire is often used for such things.
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After occupancy sensing switches became a thing the neutral is required at the switch. Many cable going from the switch to the ceiling end up being three wire now even if the feed stops at the switch box first. This is so at some point if a ceiling fan is put in there is a constant hot in the ceiling. Don't think just because it's a little more complicated (very little) means it's not recommended.