Hi there

I have a flat roof and was given four rolls of roofing asphalt rool.
The type that has to be laid with the assistance of a blow torch,
which is where my problems start.
Do I roll out the roll entirely and then heat it from the underside
and let it drop (the 2 or 3 inches) on to the roof, or do I use the
blow torch from above and gently heat the roll.

All advice greatly appreciated

Thanks