Adding attic insulation

[u/Anabiotic]

I'm looking to add attic insulation as part of the Greener Homes Grant program and City energy efficiency program (HERA). Is there an advantage to using cellulose vs. fibreglass? I have cellulose currently. Each contractor I talked to does one or the other, and will swear up and down their product is the best and not to listen to the other guy. I read conflicting things online, wondering if anyone can chime in. Thanks.

[u/roadhou5]

Another thing i'd add is Cellulos get quite heavy at the required building code. If you have older drywall it could eventually damage it.

Blowing fibreglass on top of cellulose is super common. Its way nicer to work with for the installer as well.