emt spaced off exterior of commercial building?

[croyfish]

had a buddy call me saying his boss chewed him out because he installed EMT on an exterior wall of a commercial building and secured the EMT with 1 hole straps. his boss said it was against code because moisture would build up between the wall and the EMT and cause issues. I've looked through article 110, 300, and 358 and found nothing stating such a thing. has anyone around the Chicagoland area heard of such a thing and if so can you provide the code reference or atleast the location of this information.

 

[tom baker]

You can’t find the rule as it does not exist. Respectfully ask your boss for a reference.
Welcome to the forum. You will do well with your questioning mind. There are a lot of dinosaurs in our trade.
Note there may be a local code rule on spacing EMT

 

[electrofelon]

had a buddy call me saying his boss chewed him out because he installed EMT on an exterior wall of a commercial building and secured the EMT with 1 hole straps. his boss said it was against code because moisture would build up between the wall and the EMT and cause issues. I've looked through article 110, 300, and 358 and found nothing stating such a thing. has anyone around the Chicagoland area heard of such a thing and if so can you provide the code reference or atleast the location of this information.

I hope not or else ive got A LOT of EMT to go back and fix after 25+ years

 

[Paul_Briganti]

This probably stems from 300.6(D) [2023 edition]. No such rule exists for exterior installation

 

[BarryO]

Note there may be a local code rule on spacing EMT

Always need to keep in mind that the NEC itself is just a publication by the NFPA and has no legal significance until it is referenced in whole or part by local regulation. Always check what is the legally binding regulation is in your area.

 

[Rick 0920]

There's a best practice to do electrical installations. Certainly it would be better to use a 2 piece backstrap or Minerallac strap. This would keep moisture from accumulating at the back of the conduit where it touches the wall thus keeping the conduit from rusting as quickly. These practices are more expensive and more labor intensive so you would need to charge more. There are some instances where the Code specifies that you leave an air space where walls may be washed frequently such as dairies. But for general installations, I concur with the rest of the group. There is nothing wrong with using 1 hole straps.