ScrapinSTi

If your studs are correctly on center, you have nothing to worry about with spacing , as the rolls & bats are made for exactly that... There won't be extra spaces...

And I believe the standard R Value of a roll or bat is higher than that of Blown in...

chestercheeto48

Only if it is installed correctly with no sag or gaps an if you rotate a second layer 90 degrees. The difference isn't huge and most of the time blown in is actually cheaper in the long run.

simplegreen

i was always told and have always read to leave the old stuff there unless its a hazard. Its free and regardless of the little r value it provides its still some. i left all mine in when i did my attic.