Insulating a wood sided shop?

[ace10]

Roxul Comfortbat isn't cheap but it's great stuff. R23 in a 2X6 stud bay. Fire retardant. Easy to install. Won't mold.

 

[buckeyefarmer]

I want to put 1 1/2" Polystyrene sheets between my purlins, but over $20 sheet, and they never seem to have it in stock in that size.

 

[aczlan]

Here is my thought after looking over the shop today:
Long wall:

• Calk or foam any major holes
• Wrap the inside of the wall (over and around each beam) as close as possible with Tyvec
• Put 2x4s vertically on the wall every 24". Probably flat (4" side against the wall), I might put 2x6s over the existing uprights to help tie things together better.
• Cover with heavy plastic
• Top with horizontal sheets of plywood (blowing in cellulose behind each sheet as it goes up)
• If the CFO approves funding, I would put the foam on top of the 2x4s instead of plastic, then blow in cellulose behind it

Long wall pictures:

The "grid" of 2x4s is ~3' tall by 4' wide and yes, the grey wire on the wall is going away (just need some time to pull it out).

Short wall:

• Calk the few holes (its pretty tight now but there are a couple of spots that need attention)
• Possibly wrap with Tyvec (not sure it will gain us anything, but it might be worth doing)
• Cover with heavy plastic
• Top with vertical plywood sheets
• Blow in cellulose after the 8' of sheets is up as there is a "header" at ~10' up

That should give me R19 on the long wall and R15 on the end wall. If I can get the foam insulation it would go up to R34 on the side and R30 on the ends.

Aaron Z

 

[KennyG]

I think your plan is good except that the foam on the walls is probably not cost effective. I would put that money into ceiling insulation.