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  1. #1
    Darin Ginther's Avatar
    Darin Ginther Guest

    Default NM through masonry?

    I installed conduit through the foundation, the electricians miswired, they're planning on installing a main breaker box outside the home.. I'm assuming on a masonry surface.

    I noticed today that the masons simply went around the NM wire - so now I've got NM wire sitting in direct contract with 4" of masonry.

    I imagine that the GC could "hide" this by mounting the breaker box right on the masonry.. Can someone tell me that this is against NEC. Location is Texas. Due to new regulations for rural areas, we've got to comply with 2008 NEC.

    I can't imagine that this passes withough putting the NM in conduit....



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  2. #2
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    Default Re: NM through masonry?

    Quote Originally Posted by Darin Ginther View Post
    I noticed today that the masons simply went around the NM wire - so now I've got NM wire sitting in direct contract with 4" of masonry.

    I can't imagine that this passes withough putting the NM in conduit....
    You are correct.

    From the 2008 NEC.
    - 334.12 Uses Not Permitted.
    - - (A) Types NM, NMC, and NMS. Types NM, NMC, and NMS cables shall not be permitted as follows:
    - - - (9) Embedded in poured cement, concrete, or aggregate
    - - (B) Types NM and NMS. Types NM and NMS cables shall not be used under the following conditions or in the following locations:
    - - - (2) Where embedded in masonry, concrete, adobe, fill, or plaster
    - - - (3) In a shallow chase in masonry, concrete, or adobe and covered with plaster, adobe, or similar finish
    - - - (4) In wet or damp locations

    Pretty much fits (A)(9) and (B)(2),(3), and (4) as "Uses Not Permitted".

    Jerry Peck
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  3. #3
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    Default Re: NM through masonry?

    Another observation is those weep holes in that stone work are not properly sized.

    rick


  4. #4
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    Default Re: NM through masonry?

    Also, are they using any ties? I would think we would see some.

    Plus, I think I see the through-wall flashing at the bottom, but it does not extend out to the face of the veneer as it should.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  5. #5
    Darin Ginther's Avatar
    Darin Ginther Guest

    Default Re: NM through masonry?

    Thank you for the code reference. It's extremely helpful.

    Through wall flashing - can you be more specific? The lap is hardie over a backer board. Wrap is extending 12" down from the bottom of the Hardie.. I believe it will be built into the masonry ledge eventually.

    Weep holes - I dunno how you are estimating size from that photo. They should be at least 3/8", correct? The house is foam insulated if that changes moisture concerns.


    Ties?


  6. #6
    Jeff Remas's Avatar
    Jeff Remas Guest

    Default Re: NM through masonry?

    Weep holes are to be no more than 33" apart and no less than 3/16" You normally see 3/8" open head joints for weep holes, some with a wick and some without. However, 3/16 is acceptable for a weep hole


  7. #7
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    Default Re: NM through masonry?

    Quote Originally Posted by Darin Ginther View Post
    Through wall flashing - can you be more specific?
    See attached drawing. Look for the 'Flashing' near the bottom of the brick veneer. Brick veneer is shown, same methods apply to all masonry veneers which are anchored (versus fully adhered veneers which are applied directly to the substrate wall with mortar).

    Ties?

    Go here: Technical Notes , then click on Technical Note 44B (scroll down on left to find it), then scroll about 1/4 to 1/3 the way down on the right for drawings of wall ties.

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  8. #8
    Darin Ginther's Avatar
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    Default Re: NM through masonry?

    You guys are awesome.. The references are highly appreciated and the eduation is great.

    I've done the CAD design of this house - the detail drawing and actual supervision of subs is through a GC.

    NM through conduit:
    The limestone is coming out. Conduit will be installed. I'm not particularly happy with my electrician - he should know better. The masonry guys will brick anything.


    Ties:
    I haven't been present for the masonry installation, I'll need to check on the ties. Detail drawings did not specify a masonry / stick tie system and I can't recall seeing them in typical residential construction in the area, but I may be very wrong. In this case, we're doing a 36" wall and it is non-structural in nature.

    Flashing. There are two "flashings" here - one will be at the top of the brick/hardie transition. When the rock ledge is installed, my understanding is that the flashing will be installed between mortor layers and push any possible water to he exterior side, under the brick ledge. I don't know if this changes the need for a second flashing at the footer - that flashing was included in my drawings. There is a flashing there, but it does not extend all the way out the exteriror surface of the brick... How big a problem is this? (TX climate on a foam insulated house)


  9. #9
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    Default Re: NM through masonry?

    Quote Originally Posted by Darin Ginther View Post
    Ties:
    I haven't been present for the masonry installation, I'll need to check on the ties. Detail drawings did not specify a masonry / stick tie system and I can't recall seeing them in typical residential construction in the area, but I may be very wrong. In this case, we're doing a 36" wall and it is non-structural in nature.
    Ties are required. Look down the minimum 1" air space between the back of the masonry and the wall behind it, you will ... er ... *should* ... see the ties nailed to the studs.

    Flashing. There are two "flashings" here - one will be at the top of the brick/hardie transition. When the rock ledge is installed, my understanding is that the flashing will be installed between mortor layers and push any possible water to he exterior side, under the brick ledge. I don't know if this changes the need for a second flashing at the footer - that flashing was included in my drawings.
    BOTH flashings are required.

    There is a flashing there, but it does not extend all the way out the exteriror surface of the brick... How big a problem is this? (TX climate on a foam insulated house)
    The code requires it to extent to the face, however, many installers trim it back some, about a 1/2" or so "because it looks better when you do not see the edge of the flashing".

    The *intent* of the flashing is to drain all of the water to the *exterior* face of the brick where the water can weep out and run down. Ending the flashing short dams that up, except at the weep holes. Then, at the weep holes, that cut-back flashing allows moisture to seep into the brick/concrete below.

    No brick veneer is structural.

    Brick veneer "just sits there". All it supports is itself. The ties keep it from falling away from the wall.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  10. #10
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    Default Re: NM through masonry?

    Ties are often left off. We had a school south of here involved/near a tornado. One entire brick side, two stories high, just fell over. There was not a single tie installed. They probably would have prevented the wall from falling. And the scary thing is it could have fallen over at any time with the right wind.

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  11. #11
    Darin Ginther's Avatar
    Darin Ginther Guest

    Default Re: NM through masonry?

    Ties are there. Checked this AM. They don't look particularly significant, but they are there and connect the brick to the siding of the house.

    Flashing - I looked at the flashing where they were starting to do extend the wall. The flashing is just inside (1-2mm) of the base of the brick at the bottom. We haven't done the drip edge yet, we'll address that when we get to it.

    The NM cable is being corrected.


  12. #12
    John Steinke's Avatar
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    Default Re: NM through masonry?

    Lots of luck finding new NM, or NMS of any vintage. Ordinary "romex" is type NMC, and is allowed in contact with masonry ... unless the masonry itself is a wet location, such as a foundation wall in direct contact with earth.

    NMC is not allowed in concrete, though. Please note this ... the NEC differentiates between concrete and masonry.


  13. #13
    Darin Ginther's Avatar
    Darin Ginther Guest

    Default Re: NM through masonry?

    Thanks, John.. helpful.
    GC says that they normally leave this in contact and then come back and install conduit - which sounds like an excuse to me. Most of this is clearly romex, but I'd have to confirm all of it.


  14. #14
    Fred Warner's Avatar
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    Default Re: NM through masonry?

    Quote Originally Posted by John Steinke View Post
    Lots of luck finding new NM, or NMS of any vintage. Ordinary "romex" is type NMC, and is allowed in contact with masonry ... unless the masonry itself is a wet location, such as a foundation wall in direct contact with earth.

    NMC is not allowed in concrete, though. Please note this ... the NEC differentiates between concrete and masonry.
    NM is nonmetallic cable referred to usually as NMB
    NMC is a very expensive hard to find cable which is used in agricultural uses for it's ability to withstand the effects of corrosion
    NMS is a signalling cable that came out the same year the code did away with SNM which was sheilded nonmetallic cable.
    "Ordinary" NM is subject to different rules than NMC.


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