This is your decision entirely. You do not need to be at your property while work is being carried out. However if you would like to stay the awareness is the noise factor of working overhead with tools etc.
HOWEVER
If your property has an asbestos roof being removed. For your families safety we do suggest you leave the premises while this is carried out. Asbestos fibers can be very dangerous and harmful if inhaled!
If leaving is not an option we ask the homeowner to close all windows and door plus all ventilation devices, and to stay indoors.