Penetration through metal covered wall

[bluedog225]

I want to place an outlet on the outside wall of my cabin/workshop. Bare stud walls on the inside. The layup is three-quarter inch plywood, tyvek, 3/4 foil faced polyiso, 1x4 stringers, 24 gauge steel.

Using an exterior box or an outdoor rated fixture, what’s the right way to address the wire as it penetrates the wall? Seems like it needs an anti-short bushing where it passes through the metal.

Or just caulk it in place?

Thanks

 

[Chuckster in NJ]

What type of wire are you using?

 

[75gmck25]

I always use a metal or PVC outdoor box, and then attach conduit to it to penetrate through the brick, wood, steel, etc. I try to drill and mount the conduit with a slight pitch down to the outside, and then make sure I fully caulk around the conduit penetration and outside where the top of the box is up against the wall.

On the inside it depends on what physical protection is needed. In my block garage I connect it to metal conduit on the wall and run it over to a junction box or the panel. In my house the penetration is PVC conduit going into a stud bay that will eventually be covered with drywall, so I just run the NM wire out inside the wall to the nearest junction box.

 

[WildBill]

I always use a metal or PVC outdoor box, and then attach conduit to it to penetrate through the brick, wood, steel, etc. I try to drill and mount the conduit with a slight pitch down to the outside, and then make sure I fully caulk around the conduit penetration and outside where the top of the box is up against the wall.

On the inside it depends on what physical protection is needed. In my block garage I connect it to metal conduit on the wall and run it over to a junction box or the panel. In my house the penetration is PVC conduit going into a stud bay that will eventually be covered with drywall, so I just run the NM wire out inside the wall to the nearest junction box.

I do the same, old building inspector showed me how to do it that way a long time ago.

 

[bluedog225]

What type of wire are you using?

12-2 or 14-2 NM-B.

 

[bluedog225]

I always use a metal or PVC outdoor box, and then attach conduit to it to penetrate through the brick, wood, steel, etc. I try to drill and mount the conduit with a slight pitch down to the outside, and then make sure I fully caulk around the conduit penetration and outside where the top of the box is up against the wall.

On the inside it depends on what physical protection is needed. In my block garage I connect it to metal conduit on the wall and run it over to a junction box or the panel. In my house the penetration is PVC conduit going into a stud bay that will eventually be covered with drywall, so I just run the NM wire out inside the wall to the nearest junction box.

That’s what I needed. Thanks!

 

[Bert_]

Pvc terminal adapter

 

[sparky 1971]

Pvc terminal adapter

That's what I use, and put a bead of silicone (I use Vulkem) around the hole in the wall so the box squishes it down.
Also, drill a 1/8" hole in the bottom of the box and put anti seize on the screws for both the device and cover. I have also used Fluid Film on the screws when I didn't have anti seize with me, I don't know how well it works but at least it makes me feel better about the next guy being able to get the screws out in a few years.