exemplary embodiments generally relate to a method and device for assembling a plurality of different roof - covering membranes , herein known as fitments . the particular fitment is preferably designed for the particular roof on which it is to be used . the roof measurements may be provided to a factory which may create a unitary membrane from separate pieces which may be hot air bonded together . a single machine may be utilized to quickly , and repeatably assemble a plurality of different fitments .