Double Bubble Insulation for a Pole Barn

[MoparTrucks]

All: I put up a 24x32 pole barn shop last spring and like a dumb *** didnt plan for the insulation. Anyone have any experience with putting up double bubble foil insulation or Tek Foil after the fact? I am in the middle of running electrical (takes a while when your short of cash) and then want to insulate and put on plywood for most of the interior walls but I dont know if I should just staple the double bubble over the purlins up to each rafter, and for the walls what is the best way to insulate the walls between the 6x6 posts? I know I dont want it up against the metal siding but at the same time I dont know if it touching the interior plywood is such a great idea either. Lots of conflicting information on the net but I am thinking some of you guys have run into the same situation or have personal experience.

The other question I have is the holes at the bottom where the metal siding is nailed to the bottom sill. Right now where the metal siding has the ribs it lets insects and in my case snakes into the shop; I understand that air circulation is important in preventing rot but would there be an issue with filling those holes with the window and door frame spray foam? I am not really freaked out by snakes outside but I had a small Eastern Racer scare the **** out of me the other day.

 

[fredybender]

I built an aircraft hanger like that with double bubble, and we have -20 weather here...
(down to -35C)
Insulation was great, just be shure you tape up all seams with foil tape tp prevent condensation, and vent the roof enough ; We added fibergalss insulation for the roof and provided roof vent. For that we put fur strips and held the FG with it, and provided stapling material for the double bubble.
We had the fur strips put on with self drilling screws My hanger did not have any other material after that, so I can't chime in for other materials over and /or underneath the double bubble.
As for the bottom of the sheetmetal outside walls, we had a Neoprene with UV protection, just screwed in with the roof screws, at the bottom 8" wide strip screwin at the sheetmetal, and just lying on the pavement on the opposite side, nothing more : The strip would just be tight enough on the lower pavement not to let anything in...
hope this helps
Cheers!
Fred