UF Cable in Stone Mortar

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mkgrady

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Massachusetts
Wiring a new home addition. I need to put boxes in a stone fireplace for sconces. The fireplace is built and a stone finish about four inches deep is being applied. I plan to screw mud boxes to the wall and have the masons apply the stone veneer around the boxes. I want to run UF cable to feed these boxes but I'm not sure it meets 340.12(8) (UF not permitted in poured cement, concrete or aggregate...) Does the mortar fall under these uses not permitted? If UF is not permitted in mortar, I'm thinking of running emt from the mud boxes up to the ceiling space above and running the UF down from above later.
 
Why not use PVC? It won't deteriorate, as does EMT, because of the chemicals present in the mortar.
 
Thanks for the response. The EMT is easier to bend. Do you agree the UF can not be run in mortar? If I used PVC what would the change over fitting look like? They make one for EMT. Since the EMT is allowed in mortar I doubt it would rot through in a dry wall.
 
Why not just sleeve the NM to the sconese in LFNC to the boxes and then run it back to where it can leave the raceway and do away with the need for UF cable...and you gain the flex of the LFNC and it is again just to bypass the morter issue.

As for PVC....you could sleeve it the same way...just put a bushing on the open end to avoid damage to the cable jacket and be done with it. I believe the same potential material in the morter is in the cement as well...but then again I don't know Morter too well....

I don't think protection is the issue here.....so heck I would probably use some FLEX....just for the portions that are on the fireplace.
 
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mkgrady said:
Thanks for the response. The EMT is easier to bend. Do you agree the UF can not be run in mortar? If I used PVC what would the change over fitting look like? They make one for EMT. Since the EMT is allowed in mortar I doubt it would rot through in a dry wall.
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Yes, I would agree that it cannot be embedded in mortar. You can use a male adapter (connector) to affix it to the box. Your probable right, emt would most likely last the life of the house in such an installation.
 
Oh yeah, you did say "changeover" not connector. I don't think a changeover is necessary or required for this.
 
bstoin said:
Yes, I would agree that it cannot be embedded in mortar. You can use a male adapter (connector) to affix it to the box. Your probable right, emt would most likely last the life of the house in such an installation.
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The State of New Mexico allows us to imbed UF in adobe, which is often held together with mortar. I'm interested to see if others agree that it shouldn't be done.

Jim T
 
I'm interested too. Seems to me that mortar is not poured cement, concrete or aggregate. But I don't know the chemical differences between them and mortar. If mortar is also part of the uses not permitted it seems it should be part of the list.
 
In my opinion, this stone layer is a veneer, not structural, and the mortar is not the same thing as the products the UF is prohibited from being embedded in.

I believe cable damage is the concern with concrete, not chemical reactions. To me, this is similar to embedding boxes in brick for exterior receptacles.
 
LarryFine said:
In my opinion, this stone layer is a veneer, not structural, and the mortar is not the same thing as the products the UF is prohibited from being embedded in.

I believe cable damage is the concern with concrete, not chemical reactions. To me, this is similar to embedding boxes in brick for exterior receptacles.
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I agree the uf can be embedded in the mortar but if you ever need to get to it again your out of luck. I would sleeve it.
I have done a few Hebel block house and we grove the block and use UF cable then they stucco over it. I would think it is the same for the mortar .
 
In Arizona we are also allowed to embed UF cable in mortar joints. Some of the construction here offers no alternative.
 
radiopet said:
Why not just sleeve the NM to the sconese in LFNC to the boxes and then run it back to where it can leave the raceway and do away with the need for UF cable...and you gain the flex of the LFNC and it is again just to bypass the morter issue.

As for PVC....you could sleeve it the same way...just put a bushing on the open end to avoid damage to the cable jacket and be done with it. I believe the same potential material in the morter is in the cement as well...but then again I don't know Morter too well....

I don't think protection is the issue here.....so heck I would probably use some FLEX....just for the portions that are on the fireplace.
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I took your suggestion to use LFNC. The mason liked that it was flexible. He was able to move it around to suit his stone work. I liked the idea because I didn't want to have an issue with the inspector for using UF.
 
jtester said:
The State of New Mexico allows us to imbed UF in adobe, which is often held together with mortar. I'm interested to see if others agree that it shouldn't be done.

Jim T
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I actually laughed when I read this...wonder if the NEC even has the word "Adobe" within it's pages;) ?
 
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