Yes, 8-10 lbs was about average, it could be more, but if it was much more, I got nauseous (this is called 'a clue'). It was important to stay hydrated, and salt tablets weren't a bad idea, either. TNGO, I've done a couple of roofs in the VA summer, I can relate. Constuction, in general in high heat/high humidy is tough work, but the combo of sun, tarmack, and jets was the hottest for me.