Fan Foam

osborn

Is fan foam always used? Its not used on new builds around here. Im doing a gut rehab. All new insulation and the vinyl will be over 1X subsiding.

house bldr

The biggest advantage to putting the fanfold on is to flatten the wall when going over old siding.On new construction or remodels where the old siding has been stripped it isn't necessary even though it does add a little r-value. I would definately go with a house wrap underneath if there is no old siding!