New home insulation – GreenBuildingAdvisor

Blown cellulose is about the cheapest insulating material per unit R value, and the greenest one too. It’s one of those unusual situations where you really get a win-win. If you’re doing the usual insulating the floor of an attic, loose fill (blown) cellulose is the best way to go.

One thing I would consider is that if you are planning on going up over R49, typical ceiling drywall really isn’t strong enough to support the weight of the cellulose insulation. I like to lay 1/4″ waferboard onto furring strips used to make a “ledge” on the insides of the attic floor joists, so that the waferboard takes the weight of the insulation. You can probably just use the strapping to support the waferboard to accomplish the same thing.

Bill