ent S' O.C. Al.!. SCREWS TO HAVE AMIN. 1/2' WA HEAD &A NEOPRENE WASHER. ATTACH PURUNS THRU PLYWOOD DECKING (OR EOUALITORAFIERS WITH 2-68 X 3172' WOOD SCREWS. COUNTERSINK PURL INS &ORLL 3116' DIA. HOLE THRU PURLIN & PLYV/00D. DRILL 3/32' DIA. LEAD HOLE INTO THE RAFTER. MATCH FELT PAPER. PURUNS. INSULATI