A well known SIPS panel manufacturer that I am currently dealing with has said they will not warranty their structural panel without a ventilation layer if asphalt shingles are installed directly onto the structural panel. I have recently designed and am currently building a house incorporating what I have come to believe are realistic energy conscious features ie. ICF foundation, insulated basement slab, air source heat pumps… I specified and installed the Adventech zip roof panel w/ tape with the intention of building a hot roof consisting of closed cell insulation with no venting. Is there any worry to continue with this? I am thinking that the watertight layer/ and tape adhered to the osb panel may act like the glue layer in a SIP panel. I am also entertaining the idea of using accuvent then closed cell to create a ventilated roof roof deck. All feedback is welcome. I have actually built using both methods including large depths of open cell.. I also already installed soffit venting because I am waffling back and forth.. The project related to this question is located in a coastal climate less than 2 miles to the ocean in Southeastern MA. We have built 2 Energy Star qualified homes in the past 3 years.