How to adhere to 1 1/4 rule when panel is on plywood


  #1  
Old 11-13-19, 01:28 PM
Q
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How to adhere to 1 1/4 rule when panel is on plywood

I'm mounting my panel on 2" polystyrene and 3/4" plywood.
drywall will then go on the top of that.
How do I adhere to the 1 1/4" from framing member code rule since there will be no 2x4 frame?
wires coming from the top or bottom get attached to the plywood but the drywall goes on 1x3 strapping so the wires kind of hang in this 3/4" air gap between the drywall and plywood. Is it ok as long as the wires are away from the strapping?
Presumably none can run horizontally in this method they all have to go to the floor or ceiling joists first.
 

Last edited by qwertyjjj; 11-13-19 at 02:49 PM.
  #2  
Old 11-14-19, 10:24 AM
Z
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Depending on how you (or your inspector) reads the code, as long as the cables are 1-1/4" from the sides of the 1x3 strapping, you're safe. If you picture a normally furring-stripped wall with 1x3s every 16", if you keep the cables within the middle 13.5" of the area between the two 1x3s, you're good.
BUT - it does depend on interpretation of the code (and also NEC, I'm not sure if CEC is more descriptive in terms of furred walls).

I'm not 100% sure I'm picturing this correctly though. Since the panel is approx 4" deep, and the knockouts are at various depths, I don't see how you'll be able to drywall right up to the panel, only 3/4" from the back of the panel.

In utility rooms, the drywall is usually cut out a few inches around the panel to allow cable routing. Doesn't look as nice, but works well.
 
  #3  
Old 11-14-19, 01:32 PM
Q
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Was planning on either making a box for the panel and drywalling up to the box or making a 2x4 wall only around the panel and having the drywall stick out on that section. Not sure yet - trying to save as much space on the wall as possible.
 
  #4  
Old 11-17-19, 08:21 AM
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If it were me, I'd definitely build out a 2x4 wall, probably around 26-30" wide, around the panel if it's in a finished room. It'll let you finish it nicely. The extra stud bay(s) allow the room to finish the drywall nicely and not look like it was just crammed in.

Of course it's nicer too if you can position it in a corner of the room too.
 
 

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