I already have fiberglass in the attic, but would like to add more.
Blown in will be the easiest to install, and it also has the advantage of being seamless. It is possible to rent a blower and do the installation yourself, but many inexperienced people who try that end up with a poor job in the end. Call an insulation contractor or two for a free estimate. After the job is done, insist that the installer provide you with an empty bag of the product used, and also ask how many bags were installed. The bag has a chart that will tell you how many bags are required per square foot, so you can have some assurance that the job was done correctly.
Blown in is easier, cheaper and can be a DIY project. Just make sure you don't block the soffitts that allow air to circulate.
Your best angle is to go with blow in fiberglass. ownes corning and Johns mansville both make good blow in fiberglass. Menards and Home depot in our area will lend you a blow in machine for free but make sure you have 2 people to run it and that you have a TIGHT sealed face mask for the guy in the attic along with safety goggles. No way around it either that guy in the attic is gonna get itchy, so expect that now. I put blow in cellulose over my attic fiberglass bats to bring it up to R-50 but i regret it now. I should have stuck with fiberglass. I did some research after the fact and there is some flammability issues with the cellulose i used and on top of that it is seriously dusty so i cant store anything in the attic space anymore. Cellulose was cheaper and the "green" choice but if i could reverse time I would have gone fiberglass blow in.
BLOWN BY ALL MEANS!!! SOME PLACES WILL EVEN LEND YOU A MACHINE TO BLOW IT WITH IF YOU BUY THE INSULATION FROM THEM.BAT TYPE INSULATION IS OLD SCHOOL!
