Not only that, but, as this is the roof deck, the temperature just under this metal pan can exceed 160 degrees F. in the summer. Look at the bottom part of Table 310.16 for the required ampacity adjustment for any conductors inside these conduits.

It is best to NEVER install conduit directly under the roof decking. Run your conduit and cable on the bottom part of the truss, and secure it in place with tye-wire if a ceiling is to be installed, or strut if it will be exposed.


Earl