I plan on building a 45' diameter geodesic dome in Tarpon Springs, Florida. The shell is constructed with 2x6 lumber with plywood sheething on it. What I'd like to do, is spray urethane foam insulation between the studs to obtain the maximum R-value possible...before I put on the enterior wall board. If I spray the foam so it slightly fills past the studs, can it be trimmed off flush with a hot wire? Or, can this only be done with EPS foam?