In article ,
Roy wrote:

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

My pole barn is 17 years old. I was told by Wick (since bankrupt) that I
needed to roll on 2 good coats of rustoleum on the inside of the barn
and then insulate like I would any wall. I used auto primer (thick,
heavy paint) and put too good coats on with a medium knap roller.

I then set a pressure treated baseplate and nailed it into the slab, and
covered that with a second backplate to keep the mice and rats out of
the wall. I poured a thin cement mix between the edge of the slap and
the baseplates to create a vermin proof seal.

Then I ran 2x6s vertically between the posts creating an 6 inch pocket
to put fiberglass insulation into. I covered this will T-111 that got
two coats of exterior paint on all faces (including cut edges). I
screwed the T-111 in place.

A year ago I wanted to run a couple of new circuits, so I removed a
sheet of T-111. I had zero rust in the cavity and the fiberglass was in
good shape.

I live in Michigan, so my weather is hot and humid in the summer and
cold and wet in the winter. Only the shop area is heated and that only
when I am working (weekends).

I hope this helps