Good for him, shocking that a carpenter would depend on the Boss to supply his basic tools ! Difficult to find a tape here that doesn’t have both scales. Home of the double sided tape and the Robertson screw. 
You send your major exports ( coal ) to “another” metric country. We send our major exports ( wood ) to an imperial measuring country. We’ll fully convert when “they” do. I use both systems, how about converting DaveR to metric, and his entire country as well ? Then we can finally stop using a system that began with the length of someones foot & fully- completely, embrace the, 10’s.
Well, we have serious tents here, rain & snow may be just around the next bend in the trail. So, when we pitch a tent we stake the corners, drain the perimeter & then install the tent pole. Now the tent has a pitch that allows rain to run off. Pitching a tent is a procedure, pitching a roof is…Crocodile Dundeeism (sp) ?
The names of your roof parts are quite interesting. Really, “Creeper Rafter”, yikes. Just had to remind us of all the creepy crawly beasties around those parts. Give me a pissed off Black Bear any day.