My understanding is that closed cell foam should be OK for a pure metal building (no sheathing to rot) in the south. The advantage to closed cell foam is that it adds to structural rigidity.
Open cell foam is traditionally used in higher humidity areas (south) with traditional construction (wood/sheathing).
I skipped through a lot of this so I apologize if it's repeated.
1. If you use OSB sheating and paint it, make sure you use flame retardant paint.
2. Don't forget to seal your concrete floor with epoxy.
3. Use metal building insulation on the roof applied with stick pins.
NRA LIFE MEMBER GOD BLESS OUR TROOPS ESPECIALLY THE SNIPERS! "Suppose you were an idiot And suppose you were a member of Congress... But I repeat myself." -Mark Twain
God bless Texas----------------------- Old 300 I will remain what i am until the day I die- A HUNTER......Sitting Bull Its not how you pick the booger.. but where you put it !! Roger V Hunter
Windows.......Milgard same as what I used in house in 2012
Concrete......6 bag mix......also have approx 325 sq ft parking slab outside
Wiring......armored wiring eliminates the need for conduit
Amorlite is conduit with the wire already in it. Cost about $125/roll. Works good, but looks like schit if you have it pulled where you can see it.
MC Cable sucks...big time. Very easy to pinch or short out. Greasy and nasty to work with...did I mention it sucks? Lol Pipe it in with EMT and adding a circuit is a breeze. Save the MC cable for whips to your light fixtures.