Wired a new build in Phoenix last month and I'm still going back and forth on whether metal boxes are worth the extra cost over plastic.

My partner swears by them for durability and grounding, but my old boss always said plastic is fine as long as you torque everything right... what do you guys think, is it just personal preference or is there a real safety edge with metal?

2 comments

2 Comments

michaelw261mo ago

Whoa, hold on, you wired a whole new build in Phoenix? With all that dry heat and sun beating down on everything? Man, I gotta say, metal boxes are a no-brainer there for me. Plastic gets brittle after a few summers in that kind of attic heat, and I've seen them crack when you're trying to pull wire. You can't beat the peace of mind knowing your ground path is solid, especially with all that AC equipment and stuff in a new house. Plus, if you ever have to swap a device, that metal box just holds up way better than something that's been baking for five years.

dakotam171mo ago

Gotta agree with you on the heat factor michaelw26. I've pulled too many melted plastic boxes out of attics here in AZ to ever trust them in a new build. That dry heat gets into everything, and PVC just gets crispy after a few summers like you said. Even if you torque everything perfect, the box itself becomes the weak link when it's been baking at 140 degrees for years. Plus with all the solar and AC loads in modern houses, having that bonded metal path feels way more solid for grounding. Plastic might pass code but metal just feels like the right call for the long haul in this climate.