Bat R Value Recommendation?

[mltdwn12]

I have a 33x40 pole barn. I've installed 2x4's in between the 6x6 support poles to hang bat insulation (24" centers). I put 1/2" foam board on the outside walls on the horizontal braces, so it doesn't actually touch the metal siding. But now that leaves me with 5" of space to put bat insulation. Should I use bat's designed for 2x4's (3.5" thick) which would leave a 1.5" gap between the insulation and the foam board, or use the stuff designed for 2x6 walls (5.5" thick) that would crunch up about a 1/2" when installed and then the interior wall installed. Also is it worth it to go with R-15 vs R-13? It seems the R-15 that's 24" wide is harder to find. I will be doing the ceiling after this. I'm in the eastern panhandle of WV and will be adding some kind of heat source, pellet stove or Hot Dawg type gas heater.

Thanks for the help, this site has been a wealth of info since I started updating the shop

Craig

 

[Voi]

I have a 33x40 pole barn. I've installed 2x4's in between the 6x6 support poles to hang bat insulation (24" centers). I put 1/2" foam board on the outside walls on the horizontal braces, so it doesn't actually touch the metal siding. But now that leaves me with 5" of space to put bat insulation. Should I use bat's designed for 2x4's (3.5" thick) which would leave a 1.5" gap between the insulation and the foam board, or use the stuff designed for 2x6 walls (5.5" thick) that would crunch up about a 1/2" when installed and then the interior wall installed. Also is it worth it to go with R-15 vs R-13? It seems the R-15 that's 24" wide is harder to find. I will be doing the ceiling after this. I'm in the eastern panhandle of WV and will be adding some kind of heat source, pellet stove or Hot Dawg type gas heater.

Thanks for the help, this site has been a wealth of info since I started updating the shop

Craig

Since you have the foam board over your girts and the fiberglass can't touch the metal I'd go with the thicker insulation and compress it slightly.

Since you studs are 24" on center I'd also price Rockwool.

 

[jvitez]

+100 on Rockwool.

It's denser, higher r value per inch, and water runs off of it so it won't turn into fibreglass soup like wet fibreglass batts will. Buy the 2x6 insulation which is 5.5 inches. You can cut Rockwool with a bread knife or electric kitchen knife for an exact fit. It's what I put into my attached garage and an outbuilding. I'll never use fibreglass again.