Insulation questions

[lowcountrygamecock]

Hows the best way to insulate my shop walls? I'm working on the interior rooms now which are framed with 2x4's. I bought packs of the 3.5 inch deep batts for that which worked good. But I'm wondering if you have to use batts or will the big rolls work? The rolls just seem so much cheaper. I have no idea what I'm doing so I won't be offended if someone tells me I'm an idiot for asking a stupid question.
Thanks

 

[dirttracker18]

I believe (please correct me if I am wrong) that the rolls are for ceiling/attic insulation purposes where you have a large area to cover.
The bags of batts are measure fit to your wall studs (width). Can you get the rolls in the correct width? I am assuming you are 16" OC.

 

[Bent Valve]

It is never good to use fiberglass. The best is Cellulose. But that takes some know-how to put in the walls. Not so much in the attic. Foam board would work but you need to foam or caulk the edges to keep the air out. Good luck!

 

[54FordPanel]

If I understand your question, you are asking if it's ok to use the long rolls of batts and cut it yourself instead of using the batts that comes in 93" rolls?

Yes, same stuff, you just have to cut it to length.

 

[jvitez]

More info please. Are you insulation your partition wall for heat or noise? What type of interior rooms? Will they be heated and the garage space unheated, or will both be heated? Where are you located? These will all help us help you.

 

[Falcon67]

Make sure the rolls cover the same square footage as the batts - they may not be that much cheaper. Usually, you want the faced batts on outside walls with the facing towards the heated space. On the interior, whatever. For example looking on Lowes site, the bag of batts 93" x 15" (for 16" OC studs) R13 is $41 and the 384" roll unfaced is $16 But the batts cover 106 sq/ft and the roll only 40 sq/ft. You'll spend $48 to get enough rolls to cover the same area.

 

[lowcountrygamecock]

Sorry should have given some more details. I did the same math that falcon did after I made the post and came to the same conclusion. But just for clarification there are two interior rooms downstairs that will be heated and cooled. The bulk of the footage in the shop will not be but I still wanted to insulate just in case. I'm in south Carolina do heating a 30x36 room with a propane heater is fairly easy on the fly if the walls are insulated. Cooling is a different story.

 

[dave67fd]

It is never good to use fiberglass.

Since when ? Agreed, blown in insulation may have better insulating properties but that doesn't warrant the comment that fiberglass is useless. Nine out of ten homes are insulated with fiberglass. Blown-in is considerably more expensive and has it's place but generaly speaking, fiberglasss will always win out blown-in.

Foam board would work but you need to foam or caulk the edges to keep the air out.

Foam board typically doesn't/isin't used as an insulator but as an air blocker. They are usually used to compliment each other.

As mentioned, pre-cut batts are just more convienient when insulating standard size walls. Full rolls for example can be used on odd length walls.

 

[rburke65]

Bent Valve.......from where did you get this info..? Thanks.

 

[BevoZ06]

Make sure the rolls cover the same square footage as the batts - they may not be that much cheaper. Usually, you want the faced batts on outside walls with the facing towards the heated space. On the interior, whatever. For example looking on Lowes site, the bag of batts 93" x 15" (for 16" OC studs) R13 is $41 and the 384" roll unfaced is $16 But the batts cover 106 sq/ft and the roll only 40 sq/ft. You'll spend $48 to get enough rolls to cover the same area.

Hey, Falcon -

I bought a couple of bundles of from Lowes for $41 each for 106 sq ft. Last weekend my wife went to pick up some more, but she went to Home Depot instead of Lowes. Home Depot is now selling them for $29. The only difference is pink vs yellow and Owens Corning vs. Johns Manville. I still need one more bundle of 11 batts, so I might as well go back and save another $12.

 

[buzz4041]

It is never good to use fiberglass. The best is Cellulose. But that takes some know-how to put in the walls. Not so much in the attic. Foam board would work but you need to foam or caulk the edges to keep the air out. Good luck!

********

 

[green.bubbly]

FYI, the Home Depot has unfaced R-19 on sale for 21 cents a square foot. Not sure if it is at every store. I loaded up a closed in trailer last Thursday with 78 rolls. Got 16 free because three employees could not keep count.