An apparatus for dispensing a reactive foam formulation to produce laminated panels includes a mixhead, a distribution system that defines multiple flowpaths for the reactive foam to outlets fitted with nozzles. The nozzles have multiple, spaced-apart outlets arranged at angles to each other to distribute the foam formulation evenly onto a moving bottom facing layer.

A foam roofing underlayment is provided with a reinforcement membrane having an array of fastener elements for engaging fastener elements on a flexible roof membrane. The underlayment is formed by molding foam between the reinforcement membrane and a carrier membrane. The underlayment in secured to the roof using washers having fastener elements for engaging the fastener elements of the flexible roof membrane. An anti-peel flap with fastener elements is provided around the periphery of the washers. A slip sheet is used between the underlayment and the flexible roof membrane to permit accurate positioning of the flexible roof membrane prior to engagement of the fastener elements. The interstices between the fastener elements provide lateral moisture paths to vents in the flexible roof membrane.