1925 home, raving against the Midwest winter clock to get blown in done. We pulled out really nasty old fiberglass (only 2.5”), however there is about 2’ of walkway left with some old dirty fiberglass under it. We’re air sealing and fireblocking with lumber and foam as best as we can.

We have several options:

1) leave the old dirty fiberglass - concerns about air leakage and how nasty that old stuff had gotten from roof repairs etc.

2) rip the floor boards out and remove the old insulation, then loose fill the whole thing and not worry about flooring - we would only go up for repair access, but this limits options

3) rip up boards, blow in to hoist level, then replace or reattach boards and continue blowing - slows down installation.

4) vacuum the old insulation from under the floor boards and just put a temporary block on one side of boards and blow the cellulose under the boards, then continue on top of them. - does this cause any risk or problems for the cellulose density or blower machine?

Any thoughts? Option four saves on labor but I don’t know if it will create the needed density or cause issues for the machinery?