Replies

1. 
   DaveRicheson | Dec 04, 2008 01:46pm | #1

   Conduit in CMUs

1. 
   MBaybut | Dec 04, 2008 02:38pm | #2

   CMU???

1. 
   Dam_inspector | Dec 04, 2008 03:14pm | #3

   http://encyclopedia.thefreedictionary.com/Concrete+Masonry+Unit

1. 
   MBaybut | Dec 04, 2008 04:59pm | #5

   Hey, thanks for the link. Learned something new.
   Mike

2. 
   spike999250 | Dec 04, 2008 07:17pm | #9

   Concrete masonary unit

2. 
   RobWes | Dec 04, 2008 04:18pm | #4

   Liquid Tite is easy to run or you can use EMT.

1. 
   MBaybut | Dec 04, 2008 05:06pm | #6

   Thanks,
   Vertical run obviously pose no problem but on the horizontal, do you just chip out the top of the block to go under the conduit or will this cause the block to block bond to weaken because it will fall on the mortar joint. Do you punch a hole in the side of the block?
   Mike

1. 
   CheckerContracting | Dec 04, 2008 05:09pm | #7

   Just chip out with a hammer or cut with a saw enough of a "slot" in the top of the course of block you are running the conduit (or bottom of the next course) so the conduit doesn't interfere with your 3/8" bed joint.

    Shawn

   -------------------------------------------------------------------------------

   Checker Contracting - SE Michigan

1. 
   MBaybut | Dec 04, 2008 07:10pm | #8

   Shawn,
   That's what I was thinking but wasn't 100%. What about switch and outlet boxes? I think I'm going to cover block with fake veneer stone, not sure on how to get the depth right.
   Thanks again,
   Mike

1. 
   CheckerContracting | Dec 04, 2008 08:09pm | #12

   Honestly, the easiest way (and personally I think it looks the best) is to just flush the rough-in box with the face of the CMU. When and if you put a stone veneer on, just place the device cover on the wall and hold the stone back from that edge by 1/4" or so all around. Once the stone is all on and you tool the stone joints up to the device cover it won't look bad at all. If you try to hold the device out at the face of the stone you are probably never going to get it to sit flush and pretty - unless you are planning on using a very flat faced dressed stone veneer.

    Shawn

   -------------------------------------------------------------------------------

   Checker Contracting - SE Michigan

3. 
   gfretwell | Dec 04, 2008 07:41pm | #10

   Smurf tube (ENT) is easier to work with and it can be glued directly into gray PVC boxes or you can use metal boxes but they can rust and bleed down the wall.

4. 
   renosteinke | Dec 04, 2008 08:06pm | #11

   Don't.

   Romex is not approved for wet locatioons ... and a masonry wall outdoors is a wet location. Nor will the plastic boxes anchor properly in the wall.

   Use EMT, and masonry boxes. Work together with the mason to set the piep as the wall is built. Once you're back in the house, you can use a jubnction box to transition to Romex.

   Do not run the romex inside the pipe, either. The inside of the pipe is still considered a 'wet' location .... and you'll never be able to pull the romex out if you need to replace a wire.

1. 
   MBaybut | Dec 04, 2008 08:38pm | #13

   Thanks,
   No surprise, it was the Home Depot guy that said it was ok to do the romex as long as it was in conduit. Having said that I replaced one of my outside outlets that was connected to GFCI and sure enough, that was romex. House is about 15 years old so it as to be original. I had already replaced the cable with underground cable.
   Mike

   Edited 12/4/2008 12:44 pm ET by MBaybut

1. 
   Scooter1 | Dec 04, 2008 09:27pm | #14

   They do make a form of romex which is outdoor rated.  Very thick and heavy stuff.  I wouldn't want it, though.

   But no, the white 14g or the orange 12g is a no no for outdoors. 

   Just pull wire in a conduit.Regards, Scooter "I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934

2. 
   rasconc | Dec 04, 2008 10:05pm | #15

   What would be wrong with UF? It is still considered Romex isn't it (realizing Romex is a brand but term generally used for most NM)For those who have fought for it Freedom has a flavor the protected will never know.

1. 
   MBaybut | Dec 04, 2008 10:12pm | #16

   Thanks,
   I did replace the NM that I already installed with UF. I am curious as to the GFCI on the outside of my home should have been UF instead of the white NM?
   Mike

1. 
   drh | Dec 04, 2008 10:27pm | #18

   When you say outside of your house, do you mean on an exterior wall? In this case the wire is still run through a stud bay or whatever (dry location). NM is fine. The receptacle is required to be GFCI protected because it is outside, and you need a certain type of receptacle cover (depending on whether or not this outdoor location is considered wet or damp by the NEC).Or did you mean that there is wire that is run underground, or in conduit along the outside of your house to feed a GFCI receptacle? NM cannot be buried, and should not be placed in conduit (although placing NM in short runs of conduit for protection is acceptable)...

1. 
   MBaybut | Dec 04, 2008 11:54pm | #19

   Sorry, yes I meant on the outside of the house. Thanks for clearing that up.
   Mike

2. 
   drh | Dec 04, 2008 10:22pm | #17

   NM is a different cable type than UF... the covering on both is "non-metallic", but if you are talking about cable types UF is not NM.Romex is Southwire's brand name for NM cable, like you said.

1. 
   rasconc | Dec 05, 2008 04:23am | #23

   I understand that, UF would be allowed, right?  I did not say that uf was nm just that the Romex term was generally used by many like Fridge, etc.  Maybe wrong but generally uf is more "romex" than flex, mc, bx, etc.  By definition UF would be non-metalic I would guess.

   http://www.antonline.com/p_12-2UF-WGX500-GP_325688.htmFor those who have fought for it Freedom has a flavor the protected will never know.

1. 
   gfretwell | Dec 05, 2008 05:05am | #24

   Is this a retaining wall holding back dirt or just a freestanding wall?
   That would determine whether the inside of that wall was "wet". IMHO but the final decision lies with your local inspector. If you used UF THWN in conduit or wet location rated MC cable you are covered in either case.

2. 
   rasconc | Dec 05, 2008 05:21am | #25

   I guess I am not asking the question correctly.  If UF is underground feeder, qualified for direct bruial would it not be appropriate for "wet locations"?For those who have fought for it Freedom has a flavor the protected will never know.

3. 
   gfretwell | Dec 05, 2008 08:52am | #26

   I said if you used UF, THWN in conduit or wet location MC cable you are covered in either case ...
   ... so UF will be fine, wet or not.

   Edited 12/5/2008 12:53 am ET by gfretwell

4. 
   rasconc | Dec 05, 2008 09:27am | #27

   In my quick read I thought you were saying uf had to be in conduit, my bad.

    

   Edit: You left out the commas. 

   You said first time:

   113546.25 in reply to 113546.24 

   Is this a retaining wall holding back dirt or just a freestanding wall?That would determine whether the inside of that wall was "wet". IMHO but the final decision lies with your local inspector. If you used UF THWN in conduit or wet location rated MC cable you are covered in either case.

   Cheers, I am not an electrician anyway.(;-)

   For those who have fought for it Freedom has a flavor the protected will never know.

   Edited 12/5/2008 1:32 am ET by rasconc

5. 
   renosteinke | Dec 05, 2008 02:39am | #20

   "A low patio wall with lights on top."

   I should be a little more clear.

   A block wall, such as the side of a building, is not a wet location. A block wall, in contact with the earth - as you might find in a basement - is a wet location. Based on that principle, I would consider all parts of this patio wall to be a wet location, simply because both faces are 'outside.'

1. 
   MBaybut | Dec 05, 2008 02:44am | #21

   Agreed,
   Thanks,
   Mike

6. 
   MikeRyan | Dec 05, 2008 03:53am | #22

   Done many times here in Central Florida.  It is perfectly OK to run NM through the open cells of the block.  Just punch a hole in the block and drop through.  Hammer cut another hole at the level you need the box.  Be careful not to abrade the sheathing as you are pulling it.

   We rarely have a problem with an Old work box NOT fitting into a carefully hammer cut hole.  It the few cases where we do, we use a new work box tapconed into the wall, and uses a concrete patch to float the repair in.

   If you are coming down through a wall with a poured beam, use a weatherseal conduit past the bond beam and then punch a hole through the block and continue.  DO NOT notch the bond beam. 

1. 
   MBaybut | Dec 05, 2008 05:15pm | #28

   Mike,
   Thanks. So no conduit is required and I can use NM? For the sake of clarity here's a quick sketch up of the plan.
   Mike

   
1. 
   MikeRyan | Dec 05, 2008 08:27pm | #29

   Conduit is only required where the romex will be exposed, but as soon as it is protected, the need for condiut goes away.

1. 
   gfretwell | Dec 05, 2008 08:36pm | #30

   The only question at this point is whether the inside of the block wall is a wet location and there are electrical professionals rolling around in the mud fighting about that as we speak (on another BB)
   ... but it is a friendly fight.
   Remember the punch line of the inspector joke is "... the pig likes it" ;-)

1. 
   renosteinke | Dec 06, 2008 01:42am | #31

   Greg is probably on the right track: you need to have a chat with your inspector. This is certainly the sort of project that would require a permit ... you might as well prevent a problem later.

2. 
   KFC | Dec 06, 2008 06:26am | #32

   on a seperate but related note, is it kosher to pull low-voltage line through the same conduit as a run of UF?  we've only got one easy way to get to one zone, and it's through 1" conduit that is run for an outdoor plug.

   thanks,

   k

3. 
   renosteinke | Dec 07, 2008 12:27am | #33

   While there is some room for code debate on this issue ... a lot depends on the particulars of the situation... it's considered a bad thing to do.

   Simply put, the power wiring can all too easily induce noise on the low voltage cable. which in turn can lead to other problems.

   There's also the matter of conduit fill; UF and romex generally require 1" pipe for even a single cable. Slipping a length of 1/2" pipe over romex violates conduit fill (anong other things).

   I recommend you make a separate penetration for the cable.

4. 
   KFC | Dec 07, 2008 12:53am | #34

   thanks for the feedback.  I opened a new thread on this subject, and as you say, "there's room for debate"...

   or, there's debate, anyway. LOL   Feel free to join the fray on the other discussion.  rustynail, gfretwell and england1 were hashing it out.  I don't know enough to referee their discussion, unfortunately.  they seem knowledgable.

   opening up a new channel for the low voltage will be a fair bit of work.  an extra chase or two would have been nice... 

   thanks for the input. 

   k

   Edited 12/6/2008 5:13 pm ET by KFC