I live in a town home in Maryland.
Our attic is constructed with Trusses with only 2" x 4" floor (top level ceiling) joists.
The attic floor appears to have been originally insulated with 6" fiberglass batt.
At some point there was a plywood floor / deck installed in the attic. This floor compressed the batt down into the 2" x 4" void space.
I understand that the performance of the 6" batt is now compromised by its compression.
I would like to add insulation to the attic (probably blown in cellulose) to help lower my high heating & cooling bills.
The advantage of pulling up the deck / floor is that this would enable me access to seal the top plates of interior walls and any plubming / chase penetrations as they enter the attic. I have read that these areas provide heat loss through convection and are addressed by sealing well. I suppose that removing the floor would also improve the performance of the existing fiberglass batt.
On the other hand, it is quite a bit of work to remove the decking which appears to be installed tightly. I'm not sure if in the end I'm going to be any better off thermally by removing the floor given that I'm going to blow a layer of cellulose over the whole attic.
1. Pull up the plywood floor / deck, seal penetrations as they enter the attic, and finally blow in cellulose on top the existing fiberglass batt? OR
2. Leave the plywood floor / deck in place, seal any penetrations through the plywood, and finally blow in cellulose on top of the plywood floor / deck?
Advice / Options are welcome. Thank you.