Plastics & Rubber Weekly | Dow tests finds 'slow deterioration' in common building practice Plastics & Rubber Weekly Instead of R-19 fibreglass batt inside 2-by-6 studs, the builder used three inches of R-16 closed-cell spray polyurethane foam (SPF) in 2-by-4 studs. And, instead of OSB and a house wrap, an inch of Styrofoam structural insulated sheathing with a 5.5 R ... |