Why is it some roofers use a blowtorch to heat rubber membrane roof material
for a flat roof installation with no adhesives when the instructions I
located via Google reveal the following:
". . . Smaller width pieces are often used for residential work. They are
easier to handle and there are special adhesives, solvents, and tapes that
assure leak free performance at the seams. These membrane roofing systems
also permit you to upgrade your house insulation. You can install high
performance insulations on the roof deck before the membranes are applied.
Often a thin one half inch thick fiberboard sheet is placed on the
insulation or roof deck before the single ply membrane is attached. . . . ."