Advice on running conduit through a standing seam metal roof

[corbin]

Hi! I'm installing REC410 panels on the standing seam metal roof of my shop. It has no exposed fasteners. Does anyone have any good recommendations for installing conduit through the roof, and not having it leak?

I'm debating a hole through the roof versus just running the conduit off the eave edge and into the building from there.

 

[timselectric]

just running the conduit off the eave edge and into the building from there.

Best option.

 

[time2roll]

Are there no plumbing or air vents through the roof?

Google shows lots of boots, flashing and jacks to allow conduit through the metal roof.

Over the edge is a bad look to me.

 

[sumpower]

I learned to never penitrate a roof membrane or metal roof in your case. Just one more spot to possibly get a leak that would need a later repair.
I usually transitioned off roofs with an LB conduit body.

 

[kampto]

Im using one of these. And one of those angle down conduit caps.

https://www.amazon.com/gp/product/B08HVSGR4D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[corbin]

Are there no plumbing or air vents through the roof?

Google shows lots of boots, flashing and jacks to allow conduit through the metal roof.

Over the edge is a bad look to me.

Nope, nothing penetrates the roof. It's an 1800sf detached garage/workshop; no plumbing, and no venting required.

I know it looks bad...but I am leaning towards doing it over the edge with LB's; it's on the side of the building that won't be as visible.

Thanks everyone for the replies, and thanks kampto for the boot recommendation. I also found some slick "Zilla XL Adapters" that look nice, but I think I'm going to skip the hole for this project and go over the edge.

 

[Hedges]

How about near the ridge, put flashing over it folded down both sides?

 

[corbin]

How about near the ridge, put flashing over it folded down both sides?

I guess I'm just not sure how to flash it properly; I don't have metal roofing skills. This would definitely look cleaner, but I don't think I'm too concerned about the looks. I appreciate the ideas though!

 

[Checkthisout]

Lots of ways to do it. If done near the peak then it never has much water run over it.

I'm going to guess it's a nice looking building if you spent the cashola on a concealed fastener roof.

You just use a standard plumbing boot but urethane sealant and an LB with some kick out flashing works good too.

It's akin to the body seam sealer they use on vehicles and lasts forever on roofs.

 

[time2roll]

For best look drill and seal under the panel.

 

[TechRider]

I just went through the same thing and just wrapped around the roof. If I ever change my mind, it's easy to remove.

 

[wpns]

Another vote for over the edge, roof penetrations are just future problems

 

[timselectric]

I just went through the same thing and just wrapped around the roof. If I ever change my mind, it's easy to remove.
View attachment 212649

For future reference, and for everyone else.
A continuous conduit bend of more than 90° is a big no no.
While it looks neat, it would not pass an inspection.

 

[EVM425]

Actually it's ok to use this kind of bend, as long you are not going over 360 degrees between the pull points.
It's called a "Shepard hook". I saw it a few times, and used it by myself also.

 

[TechRider]

Everything I found was no more than 3 90's in a pull. I have a little less than 3. The final bend to get on the roof is about 67°. I have an LB at each end.

This shows a little better. (And also my first ever conduit bend so I didn't think I did too bad.)

 

[wpns]

A continuous conduit bend of more than 90° is a big no no.
While it looks neat, it would not pass an inspection.

My AHJ installed this for me, so I know it meets their requirements. What's wrong with a more-than-90-degree bend (from a technical POV, not 'cuz code sez so')?

 

[timselectric]

It's called a "Shepard hook".

Correct
And it's illegal.

I saw it a few times,

That doesn't make it ok.

 

[timselectric]

Everything I found was no more than 3 90's in a pull.

It's actually a limit of 360° of total bends, between pulling points.
And no single continuous bends of more than 90°.
But most people follow the 3 90's rule of thumb. (Myself included)

This shows a little better. (And also my first ever conduit bend so I didn't think I did too bad.)

It is straight and well performed.

 

[timselectric]

My AHJ installed this for me, so I know it meets their requirements.

That looks like flexible conduit. If it is, then it's fine. Because it's assumed that the conductors are placed in the conduit before it's bent.

What's wrong with a more-than-90-degree bend

Too much friction and tension placed on the conductors, when being pulled through the conduit.

 

[timselectric]

I'm going to concede this one to interpretation. (As many things in the NEC are)
The code has always been "not more than the equivalent of 4 quarter bends (90°), in a single run. (Which is a total of 360°)
But, after a bit of research, just now.
Some people don't believe that "quarter bends" (90°) is the maximum allowed single bend radius. (I always have)
But since it's open for interpretation. It's up to your local AHJ (and their interpretation), if it will pass.
It has failed inspections in my area. But could be acceptable in yours.
I can only say that it's never been something that I would do.

 

[Partimewages]

I have seen it pass also. But only where the inspector couldn't see it!

 

[mciholas]

Some people don't believe that "quarter bends" (90°) is the maximum allowed single bend radius. (I always have)

Any 180 degree bend can be two 90 degree bends with a very short straight section between them., say 1 inch long. So who is to say any 180 degree bend isn't two 90 degrees bends with a very short straight section?

I think interpreting the "quarter bend" as limiting the bends to 90 degrees is wrong. It is just that the most common bends are 90 degrees so you can count them that way. If more than 90 was an actual limit, the code would say that explicitly.

Indeed, it says the "equivalent of 4 quarter bends", which strongly implies you got 360 degrees to work with no matter how you cut it up since that would be "equivalent".

Mike C.

 

[Hedges]

The equivalent of 4 quarter bends (90) would include 8 eighth bends (45). Or 2 half bends (180), even though I haven't seen such for sale.

I think one 180 degree bend would be better than two 90 with the bit of straight between them, and maybe a splice. The wire just holds its radius all the way around.

I'm not big on following rules just because they're rules. I always want to ask, "But why??"
Although, I'm going to hold my tongue when dealing with an inspector or cop.

 

[timselectric]

Any 180 degree bend can be two 90 degree bends with a very short straight section between them., say 1 inch long. So who is to say any 180 degree bend isn't two 90 degrees bends with a very short straight section?

I think interpreting the "quarter bend" as limiting the bends to 90 degrees is wrong. It is just that the most common bends are 90 degrees so you can count them that way. If more than 90 was an actual limit, the code would say that explicitly.

Indeed, it says the "equivalent of 4 quarter bends", which strongly implies you got 360 degrees to work with no matter how you cut it up since that would be "equivalent".

Mike C.

This is why I said that I would concede this one to interpretation.
I have always interpreted (as I was taught) to be the equivalent of 4 quarter bends. Which can be a combined total of multiple lesser than quarter bends, not to exceed 360° total.
And I am not alone in this interpretation. As I have never seen an electrical conduit bender designed to perform a bend greater than 90°.
If you have, please provide a link to it. It might change my mind on the interpretation.
I still wouldn’t do it. But I might not view it as unprofessional when others do.

 

[robbob2112]

Ok, maybe I am being dumb but I am gonna ask

Why not go over to an edge and over the side where there is presumably a lot less overhang?