Need advice on insulation in Florida !

I am converting a new 10x20 storage shed into a cabin in central Florida. The shed came from cook portable warehouse in Ga. The inside walls are 2x4 16" on center and I will finish with 1x6 knotty pine boards for that log cabin look I love so much. My question is this I want to insulate the crap out of the walls to help with cooling cost. I use my heat maybe 30 days out of the year so 99% of the time the goal will be to keep it cool inside. Looking for ideas. It's only 200 sf. so cost is not a big deal. Thought about the great stuff foam around all the studs where they meet the outer wall, then maybe a foil radiant barrier, then pink fiberglass batts and maybe another layer of foil type radiant barrier which I would put the pine paneling directly over or maybe roofing tar paper like I used for floor tile many years ago. Any advice would be helpful. I Have to finish the ceiling also which is built just like the walls.

Are you counting on insulation alone to keep it cool in summer? I don't see how you can do that without some type of A/C, because A/C doesn't just lower the temperature of the inside air, it also dehumidifies it. And dehumidified air is a lot more comfortable than sweating out dew points in the 70s.

A 5000 BTU A/C unit should be more than enough to keep it cool.

No way jack, I got a new Lg 5000 btu unit to use after I finish it. My ac is a very valuable asset !

how hard is it to just remove the skin and put the radiant foil over the whole wall like a tyvek?

is the outside metal or wood

screwed or nailed

i hesitate to use foam products in such a sealed environment, but the instinct to get a radiant and air barrier in place would seem to be a good one.

have you thought about trying to incorporate those underground cooling tunnels , or are you in the flat swampy part

how about grapes or vines that can add some respiration and shade to cool the outside

energy costs are only going to increase, so as much as you can eliminate the need for ac the better you'll be in the long run

The 2012 IECC building code for Climate zone 2 has prescriptive requirements of R13 for wood frame walls/floors and R38 for the ceiling. Most important is an ACH50 of 5 or less for the blower door tested infiltration. My bold prediction of the day is that the upcoming 2015 revision will have a tighter requirement for your climate and I would suggest getting to 1.5 or 3 at least. It may not make sense to pay someone to blower door test your small project but you should do what you can to make it airtight or the increased insulation is wasteful.

Anything could work for your situation but two things sound off to me. Are you saying you would use great stuff in the corner of the stud and sheathing intersection? That would probably be a complete waste. A better strategy is taping the seams and transitions from the exterior. You might want to consider getting a DIY two part spray foam kit for your cavities or encapsulate the entire thing. I would also consider wrapping it all up in strawbale and building a completely separate roof above it. Orient your windows to the south and try to shade the East and West walls (especially windows) with overhangs or landscaping. Choose a bright white roof color if possible.

Radiant barriers can add some performance but they need to have an airspace to function. Dont put radiant barriers to the interior whatsover! That would be a vapor barrier on the wrong side of the wall for your climate.

The outside sheets are nailed to the frame so I can't really take the skin off its called lp smartside. I like the idea of taping vs spray foam where the studs meet the outer wall. I will placing it in about 80% shade. The roof has standard shingles went with a light color for those. Never understood why builders put black shingles on homes in Florida of all places. So I'm guessing two layers of radiant barrier not a good idea. The underground cooling is not really an option where I am. Thanks for the help !