I am currently building a cathedral ceiling room addition on a very limited budget. I have been fortunate to obtain many building materials at low cost. The R19 kraft faced fiberglass for the ceilings and walls (1000 sf) cost me only $200. It is going to drive me crazy to spend another $200. for the plastic insulation baffles at Home Depot. I can purchase a roll of housewrap ( 9' x 100') for $30. This would certainly fill the role as an air barrier in my rafter bays. Does anyone out there have a nifty idea on how I could maintain a 1 1/2" vent chute between sheathing and house wrap? It needs to be simple, time effective and cost effective. Other particulars : 2 x 8 rafters, 16" oc, 5/8" OSB sheathing; plan to cut housewrap 16"-18" x 140" to fit each rafter bay.