Patent ID: 8776480

Claim:
A method for installing a roof assembly onto a building having a framework, the method comprising: coupling a first structural layer to the framework of the building; laying an insulating layer including a roof insulation panel made from foamed insulation material onto the first structural layer so as to be positioned above the first structural layer; coupling a ventilating purlin to the first structural layer adjacent the insulating layer such that a lower edge of the ventilating purlin abuts the first structural layer and an upper edge of the ventilating purlin extends above the insulating layer; and coupling a second structural layer into abutting contact with the upper edge of the ventilating purlin such that the second structural layer and the insulating layer are separated by a ventilating layer of air space and such that a weight load of the second structural layer is transmitted through the ventilating purlin to the first structural layer, the ventilating purlin extending through the insulating layer such that the insulating layer does not bear any of the weight load of the second structural layer, wherein the ventilating purlin includes at least one ventilation opening positioned to enable air flow through the ventilating purlin into the ventilating layer of air space.