Ceiling / roof insulation for small shed

[Shovelhead]

Finishing up wiring this 12x20 portable shed and scratchin my head about how to insulate the ceiling. Shed has a metal roof. No special insulation foil backed plywood for roof decking. No soffit vents, no vents at all.

Insulation methods are all over the map these days in my mind.
You got your standard method with venting soffits and ridge, gable vents...
then you got your spray foam seal everythinng like a cooler. Which I believe some say requires fresh air intake/exhaust.

This shed will be used as a climate control storage shed for our furniture until a house is built. I have a window A/C for it. Heat is not a main concern in my climate in Deep East Texas.

Once it ends it's life as a furniture storage room it will be back to a storage shed for mowers and other outdoor equipment. So I dang sure ain't spending money to spray foam the sucker. I have roll batt insulation for the walls.
I was thinking of bonding foam board to the back side of whatever ceilig material I use. Likely 3/8 plywood, not sure yet. Ceiling will be screwed to 2x4 trusses so there will be an open space between there and the roof. Will that work worth a ****? I'm sure it will help some.

Should I cut some gable vents on each end? Should I even jack with ceiling insulation and just let the A/C roar. It's not a "permanent forever" climate controlled shed.

All suggestions welcome for this particular application.
Thanks

 

[couch67]

If the cooling requirement is temporary and you are planning to put a ceiling in anyway, just go with the ceiling (you mentioned plywood). Install gable vents at both ends in the attic and you should be fine. I wouldnt insulate if its going to be temporary and just for furniture - I'm sure you can get away with it being a little warmer than normal and just get it under 90 something degrees....

 

[Shovelhead]

Thanks couch.
That was another thing I thought about. Just plywood and no insulation above.

 

[Hank11]

Put in gable vents and then hang a ceiling of foam board - the kind with aluminum foil. Foil side up and tape the joints. Buy the foam as thick as you want to spend. Drywall screws into the trusses and big plastic washers. Later on you can finish it nicer if you want, maybe screw some dry wall over it.

 

[duneslider]

I sort of doubt you will save enough money by insulating it to cover the cost of all the insulation for such a short period. I am assuming you are talking about just a handful of months, maybe a year? What's it cost to run a window ac unit for that long? Maybe 50-75 bucks a month?

Air sealing might net you more than insulation but still...

May depend on what temp you are trying to maintain. Maybe putting in a ceiling of foam board would help a little as it would decrease the area you are needing to cool and might slightly reduce the amount of heat coming in. If you are trying to maintain say 90 degrees, how many days of the year is the temp over 90?

 

[Black300zx]

How many months are we talking and how well climate controlled do you need? Fine heirloom furniture, or are you just trying to prevent it from baking in a 120degree shed?

Around here, a 10x20 climate controlled and secured storage unit goes for about 300/month. Non-climate controlled is about $200. Being part of a large building, I'd think non-controlled units would still be much better than a non-controlled shed. Have you looked at how much time/money/effort you'll spend using your shed to store it versus just renting a unit?

 

[Bretny]

I would cut foamboard to fit between the roof rafters and can foam around them. Sounds like alot of work but once you get going it's not bad. You can even get setup to cut the foamboard on a table saw and really get things up quick. One screw into the roof perlin will hold up the foam board just fine and once its foamed at the edges it's not going any where.

 

[Syberia]

I sort of doubt you will save enough money by insulating it to cover the cost of all the insulation for such a short period. I am assuming you are talking about just a handful of months, maybe a year? What's it cost to run a window ac unit for that long? Maybe 50-75 bucks a month?

In OP's climate (hot and humid), it may not be an issue of cost savings. Without insulation, a window A/C may not be able to keep the place cool at all.