I have a 1937, 1 1/5 bungalow style house that is planned for a finished attic. It is built without soffit vents for air-flow beneath the A frame roof. Instead of restructuring to create an air gap, vapor barrier and movement of air, before insulation, to address air condensation, can a spray foam type product be used between the trusses? Would the removal air beneath the roof trusses prevent air condensation/ moister and possible rotting of roof trusses in the future? If this is possible, what type of sprayed foam insulation is recommended? Live in Cincinnati, Ohio, zone 5. I am most concerned about insulating my attic for living space while internally preventing air condensation and externally causing ice dam in the winter, which causes the destruction of my gutters every year.