SWMBO has finally retired and we're fixin' to abandon Houston and move to the
mountains of eastern Tennessee. The place we bought has a 5 year old metal
barn, aka, The Shop. The shop is 38x40 with 14 feet to the joists and has 8
large skylight panels in the metal roof. The former owner blocked off four of
these because it overheated the barn in the summer. There is an insulated room
about 12x20 in the back left corner of the building.

The building is pole construction, well, actually 6x6 posts with 2x6 or 2x8
stringers on the outside about 2 feet apart. The metal siding is fastened to
the stringers. There are X braces between the posts fastened to the stringers.

I don't know anything about metal buildings except that the shed in the back
yard severely rusted after 12-15 years. I am concerned insulation might create
a dead pocket against the metal that would eventually cause rust damage to the
siding. I do not know if there is a moisture barrier under the slab.

I plan to heat with propane and install a/c in the shop area. I have not decided
how much square footage to convert to the shop, but will probably keep one bay
(13x38) unconditioned to store trailer, mowers, tractor, etc. I won't be there
until the middle of next month, so that's about all the info I can supply

So what is the best way to insulate this thing so the walls don't rust? Closed
cell spray foam? False wall with batt insulation and gap between it and the
metal siding? Other???

I shudder at heating costs with 14 foot ceilings. I'm willing to replace the
existing room walls if that is needed. That room needs more outlets anyway.
Maybe I'll only ramp the heat level up to minimum gluing temperature in the
winter, say 55-60F (13-16C, Jeff) . This new shop is the first time I've owned
anything with a metal skin, outside of my pickup truck and BBQ smoker. Couple
of my old trucks could have been mistaken for a smoker.

Thanks for any help. Roy