With all the remodeling going on we haven’t given up on our super insulated goal. All the downstairs 2×4 walls were furred out to 6.25″ thick. Each bay was filled in with a layer of 0.75″ foil-coated EPS foam board, followed by 2″ foil-faced R-max foam board, followed by 3.5″ high density fiber glass insulation (total: R31). We attempted to maintain the air seal (which is basically perfect on the second floor), by spray foaming the edge of every foam panel and between studs and gaps. The band joists received a similar treatment of layered foam inserts and spray foam.
We hired out all the fiberglass work including R30 batts under the house. The ceiling bays had twenty inches of blown-in insulation, for a minimum of R60. Most windows were spray foamed into place or tucked with insulation scraps. Lee needs to spray foam the light fixture boxes in the top attic before it’s blown with loose insulation, but otherwise we are nearing the end of the endless insulation.
We also sound insulated with fiberglass batts between the two floors and added rock wool batts to the laundry room, office, bathroom and master bedroom walls. The laundry room is in the center of the house, so we insulated there to reduce the echoiness of the whole house. The office insulation was particularly important, since Lee works from home. Now Sidney and all her friends can practice playing the drums and bagpipes and it won’t disturb him.