Crawlspace Wall Dilemma

[George Stolz]

I was recently approached by someone looking for answers on a project he is working on. I offered the best answer to a particular problem I could think of (along with a couple lesser answers, IMO), but never really felt like I had the perfect solution to the problem. I'm hoping for some experience to fill in the gaps on this.

Imagine a crawlspace concrete wall, with holes drilled in it prior to framing. The person (doing their own work on a properly permitted job) then began framing, and the holes were below the joists. So, in order to go from one side of the concrete wall to the other, it would be necessary to drop below the joist level, penetrate the wall, and return to joist level and continue the run.

My solution was to ram-set some 2x4s to the wall, and use them as a chase for wiring. I figured conduit runs would not be especially productive, because the panel is located some distance from the walls in question, and it would be necessary to pull all at once and have a good guess at the length before doing so.

Any better ideas?

 

[Sparky Joe]

Your question is not very clear. If this is exposed work you shouldn't be using romex and if it isn't exposed then why all the added 2x4's and why drill through the floor joists, it will just weaken the floor and stapling to the bottom of the joists every 4 feet or so is sufficient.

It looks like your concrete wall is what I always call a 'stem wall' in a house foundation. Just run the romex nice and neat (craftmanlike manner) and don't worry about it. Even ram-set some romex straps if you like.

 

[M. D.]

George, How about some wire guard like the power companies use ?

 

[tshea]

Based on your picture, I think you have a pretty good innovative idea! If the HO is doing the job, time is not a problem.
The real obstacle is the concrete wall. Another option I see is to drill another hole through the concrete (too much time).
The key here is to protect the romex, and it looks like your method does just that.

 

[tshea]

If this is exposed work you shouldn't be using romex and if it isn't exposed then why all the added 2x4's and why drill through the floor joists, it will just weaken the floor and stapling to the bottom of the joists every 4 feet or so is sufficient.

Why? What is your justification? The romex is routed through holes drilled in floor joists.

Why do you say drilling joists weakens them? There are numerous threads explaining the proper place to drill joists without weakening them.

 

[George Stolz]

If this is exposed work you shouldn't be using romex...

Why not?

...if it isn't exposed then why all the added 2x4's and why drill through the floor joists, it will just weaken the floor and stapling to the bottom of the joists every 4 feet or so is sufficient.

Not legal, see 334.15(A).

Just run the romex nice and neat (craftmanlike manner) and don't worry about it. Even ram-set some romex straps if you like.

Can you elaborate on this method?

 

[George Stolz]

George, How about some wire guard like the power companies use ?

I don't know of the product you're speaking of. Can you provide a link? Is it expensive?

 

[George Stolz]

Based on your picture, I think you have a pretty good innovative idea!

Thank you.

I don't know if it's the best idea, though.

Another option I see is to drill another hole through the concrete (too much time).

Too much time, and if what I'm picturing is accurate, I don't see how he'd get a drill in there to drill another hole up high. That was my first thought, too.

 

[celtic]

What's above the wall?

 

[infinity]

Why not?


Not legal, see 334.15(A).


Can you elaborate on this method?

How would this not be following the surface of the building finish if attached directly to the concrete wall? Since you're talking about a crawl space is there an issue with possible physical damage to the cable? If not, than it could be attached to the wall or if you so choose to running boards mounted to the wall. This would make it easier to secure the cables.

 

[don_resqcapt19]

George,
Why do you have to drill the joists in a crawl space?
Don

 

[iwire]

George,
Why do you have to drill the joists in a crawl space?
Don

He cited 334.15(A) which requires exposed NM to 'closely follow the building surface'.

I think the young punk may be correct.

 

[dlhoule]

What's above the wall?

and how thick is the wall?

 

[Pierre C Belarge]

In a crawl space it always depends on the situation at hand, which of course we cannot see.
The standard type of crawl space we have in the northeast would not (IMO) pose a problem from physical damage. I also would staple the NM cable to the bottom of the joist... isn't that part of the finish??? I say we can take example of 334.15(C) as guidance to the fact it can be installed without boring holes.

 

[George Stolz]

What's above the wall?

We don't discuss what's above the wall. Evildoers live above the wall. We stay in the crawlspace and they can't hurt us.

Sorry. Had a "The Village" moment.

From what I understand, the flooring rests directly atop this wall. I reckon the floor joists are secured to the concrete, or something. The framing of this structure is problematic at best. There is no attic to use, it's a cabin in the boonies with exposed logs, that sort of thing. In fact, the framed walls resting atop this concrete wall are inaccessible from below because of the framing. There are columns in each corner of the kitchen, which rests above this crawlspace area.

So, essentially, the only path to the far room is from below.

 

[iwire]

When I first read Georges post I kind of scoffed at it (Sorry George) after reading his cite I agree with him.

We ca not per code run NM on the bottom of joists in a crawl space.

I say we can take example of 334.15(C) as guidance to the fact it can be installed without boring holes.

That right there is the problem.

First we have this.

334.15 Exposed Work.
In exposed work, except as provided in 300.11(A), the cable shall be installed as specified in 334.15(A) through (C).

OK so when we look at .11(A) we find that the cable shall closely follow the surface of the building finish or of running boards.

IMO running along the bottom of joist is not in the least 'closely following the building finish'.

Than we look at .11(C) and we find that (C) is a deviation from the main rule in (A). (C) allows larger cables in an unfinished basement to be installed under the joists or smaller cables to be run through bored holes.

So that said I don't see permission in a crawl space to run any size cable under the joists or even run through bored holes if the cable will be exposed.

That George is a sharp one.

 

[George Stolz]

How would this not be following the surface of the building finish if attached directly to the concrete wall? ... If not, than it could be attached to the wall or if you so choose to running boards mounted to the wall.

How would you attach romex to concrete? The only way I can picture this is with running boards running up the wall. You are envisioning two options, I can't see one of them.

Since you're talking about a crawl space is there an issue with possible physical damage to the cable?

I don't think so. I wonder what others think?

Why do you have to drill the joists in a crawl space?

He cited 334.15(A) which requires exposed NM to 'closely follow the building surface'.

I think the young punk may be correct.

What? I can't hear you over the loud rock music and the motorcycle in the living room.

I just don't see a way around it, I think it's exposed. Then again, is an attic exposed? I typically run across the trusses in an attic, and it's as exposed as a crawlspace. But, then again, we're given permission to go nuts in an attic, away from the attic access (320.23). Interested to hear other opinions on this.

I also would staple the NM cable to the bottom of the joist... isn't that part of the finish???

I would say it's "unfinished". Therefore, there is no building finish. That leaves running boards, or drilling through the joists, doesn't it?

I say we can take example of 334.15(C) as guidance to the fact it can be installed without boring holes.

Can you explain?

 

[iwire]

How would you attach romex to concrete?

3/8" one hole clips or the tie wraps that have a hole for attaching them to a surface.

How about a little panduit?

 

[George Stolz]

3/8" one hole clips

Are they "similar fittings designed and installed so as not to damage the cable"? I don't think they're designed for NM cable.

Another aspect I'm not comfortable with is physical contact of the NM cable with the abrasive concrete. I guess it would depend on the finish of the concrete, and how securely the cable was pressing against it.

or the tie wraps that have a hole for attaching them to a surface.

That would work. The only thing against that would be physical damage, but that's in the eye of the beholder. I've kinda come to the conclusion that physical damage is more of an equation than a definable term.

How about a little panduit?

Thanks for editting in the picture, I had no clue what that was!

That looks cool.

 

[macmikeman]

George, forget the panduit, it is too nice to stick in a crawlspace. Take a measurement for a 2 x 4 from the top of your holes to the bottom of the joist.. Cut each end at an opposing 45 degree. Nail it to the bottom of the joist and the other end, ramset into the concrete wall. An angled board for you to staple your runs to, an added brace for the structure, and your romex needs no attachment to the concrete.