insulation question

I have reviewed all of the stickies and also have Rod's book (great help) but I have one question about the insulation type to go in interior walls. I have built the typical double 2X4 wall with 2" air gap between plates. Studs are 16" OC. I am still confused on the insulation type best suited for the stud walls. Rods book mentions glass fiber insulation as do the IRC wall section specs. I have also seen many people on this site using rockwool or OC 703 type in their stud walls. I would like to know what exactly the meaning of glass fiber insulation is in this context. Are we talking about typical pink rolled fiberglass house insluation? This is what I was originally planning but I need to confirm. I already have to buy a quite a bit of 703 type material for traps and treatments. I would hate to have to buy enough to fill all of my stud cavities (and have to cut it to fit 16"OC) but if that is what is spec'd so be it. Little help?

D.B. You were correct in assuming the pink fluffy stuff. NO paper backing however. Peace Tom

I used R19 in the same type of wall you're building and it worked great. I chose r19 to have it be a bit more condensed and stuffed in there. I'm thrilled with the results.

thanks for the replies guys. Isn't the R19 designed for 2x6 walls? I was thinking of using it but I didn;t want it to stick out into my air space too much. Can you use the faced product with the facing along the back of the frywall, thus not creating another "leaf"?

drywall not frywall , sorry

Your frywall...oops I mean drywall :lol: :lol: The experts say not to but many have done it anyway. I have also seen many people put the paper outwards. To what ill effect? I have no idea R-19 is 6&1/4" thick R -13 or R-15 is for 2x4 and its 3&1/4" thick I also put R-19 in my 2x4 walls Peace Tom

The ill effect may be that the kraft paper can smack the sheetrock inside the air cavity as sound pressure is applied to the walls. Is that stir fryed or chickenfryed?