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Embed wire in floor? #70272
10/02/06 10:08 PM
10/02/06 10:08 PM
Grover  Offline OP
Joined: Jan 2005
Posts: 109
Sebago, ME, USA
My customer - builder - personal home - has constructed a "post and beam" style house - exposed beams in large kitchen - dining - family room area. Beams are 8x10. 2nd floor is decked with 2x6 planks.

He wants me to run up inside wall to 2nd floor, and then run out - across the decked floor - to hit the center of the beam and drop down to the room below centered on the beam, for the fixtures - 3 of them - cut in fan boxes - about a 6' run each across the floor. He proposes that he route a groove from the wall out the the point of drop down and protect it - overlay floor will be floating type "Pergo". Groove needs to be 1 1/4" to top of wire - right? If groove is 1 1/4" does it even need protection?

Several things come to mind.... romex inside EMT/RMC. MC wire. RWS Conduit. Metal wiremold. Could terminate the EMT/RMC with adaptors and bushings - could drill the 8x10 to accomodate the radius for the MC or RWS. Can't seem to find anything in the code that governs this.

Ideas? Suggestions? Appreciate the help.

Work Gear for Electricians and the Trades
Re: Embed wire in floor? #70273
10/02/06 10:57 PM
10/02/06 10:57 PM
Peter  Offline
Joined: Jun 2004
Posts: 92
San Diego
Would the groove be parallel to the grain of the 2 X 6? I not, then this would seriously harm the strngth of the wood. But you and he know that.
If less than 1 1/4" depth, then you could use nail plates [or equivalent]. Perhaps 1/2" EMT with individual THHN wires. You might want to fill in the rest of the cavity with some grout or something. Since Pergo is a floating floor you don't really have to worry about nails.
Be wary of cut in boxes in the 8 X 10 bean. The most tension in a structural beam is on the bottom side.
Hust some ideas.

Re: Embed wire in floor? #70274
10/03/06 04:42 AM
10/03/06 04:42 AM
e57  Offline
Joined: May 2003
Posts: 2,876
I reluctantly had a simular situation... But commercial, and local AHJ demands metallic methods here. (Different story) It had timber and much heavier decking. 4x6 T&G I think... Then a wood floor on that.

300.4(2) Notches in Wood. Where there is no objection because of weakening the building structure, in both exposed and concealed locations, cables or raceways shall be permitted to be laid in notches in wood studs, joists, rafters, or other wood members where the cable or raceway at those points is protected against nails or screws by a steel plate at least 1.6 mm (1/16 in.) thick installed before the building finish is applied.
Exception: Steel plates shall not be required to protect rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.
That said, the notch could be 1/2" deep X 5/8" wide (12/2 NM) or big enough for what ever cable you use, and have a 1/16" plate of steel over it. It does not say that it has to be a "Nail-plate" or listed.... Just steel plate.

Structuraly its his house, and aparently edjucated on the damage that he might be under taking with all of this notching? If so, I would tell him, "it's like Pontiac - wider is better, or in this case deeper is better." Then have him steel plate it entirely when it's done....

Mine was a mix of RMC and MC. I used pipe to get more citcuits to areas without haveing to make a whole bunch of notches. And MC jumping point to point. I pre-bent portions of the pipe and traced where I wanted to go. The pipe didn't need protection, and after watching this guy chisle a reccess for the 3/16 X 1 1/2" flat stock to put over the MC, I suggested just using an electric planer, and it worked well. Bottom line I hated doing the job, and I was constantly waiting for some labor/carpenter to butcher me a path, and forcing him to radius bending portions of it. It was irritating! But worked out OK.

If you need to pipe plan out very well. I had to come from walls - 90 onto the floor parralel to the wal, then 90 or kick out away from the wall to keep it flat. This was with 1/2" RMC. Which I preffered, because I have seen EMT squashed before... If you can do it in EMT, you can go to the back side of a 2X wall notched below the bottom plate and not have the radius stick out. It will just barely miss the face of the base trim.

FYI some of the 30/40's Frank Loyd Wright style and some of the Arts and Crafts homes here are done in a mix of pipe and K&T/loom in simular ways. But then short radius benders were still available and legal.

Now.... all that wood, and the guy is opting for Pergo?! [Linked Image]

[This message has been edited by e57 (edited 10-03-2006).]

Mark Heller
"Well - I oughta....." -Jackie Gleason
Re: Embed wire in floor? #70275
10/03/06 10:28 AM
10/03/06 10:28 AM
Almost Fried  Offline
Joined: Sep 2006
Posts: 98
Madison County, Ark. USA
I would rout a <7/8" groove and place emt inside, flush with subfloor.

I live in a rented home with Pergo, think it sucks. I have worked in many other homes with the stuff, once you have experienced it, few people like it. It is like living on loose formica, the harshg accoustics it creates are hard to live with, it is just another tacky "solution" that is more expensive than the real thing that it mimics...IMNSHO...imagine that this imaginary, printed facsimile is real wood...yeechh!

Re: Embed wire in floor? #70276
10/03/06 07:25 PM
10/03/06 07:25 PM
HLCbuild  Offline
Joined: Dec 2004
Posts: 209
Herndon,Va USA
If you route a groove in the floor, you better hope someone doesn't change their mind and change over to hardwood flooring that gets nailed in place!

Re: Embed wire in floor? #70277
10/03/06 07:48 PM
10/03/06 07:48 PM
e57  Offline
Joined: May 2003
Posts: 2,876
Thats what the steel plates are for. A pin nail is not going through a nail plate. Where as a Framer out of a gun or self-drilling rock will....

Mark Heller
"Well - I oughta....." -Jackie Gleason
Re: Embed wire in floor? #70278
10/03/06 09:18 PM
10/03/06 09:18 PM
gfretwell  Offline

Joined: Jul 2004
Posts: 9,343
I wouldn't bet the farm that a nail used on real oak flooring, shot from a gun, wouldn't pierce a kickplate or EMT.

Greg Fretwell


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