In lieu of fiberglass insulation, Rockhill specs Xcell spray-in cellulose because of its “great R-value.” Made from recycled newspaper and treated with fire-retarding boric acid, Xcell is said to prevent air leakage more effectively than conventional batt insulation. Its manufacturer also claims it reduces outside noise and sound transfer between rooms. Central Fiber Corp., 800.654.6117; www.centralfiber.com.
