How do you make any money with that much overtime? if your not paying O/T but some sort of subcontract agreement you are either breaking federal labor laws or in some serious gray area that will take a lawyer and much more $$ to clear up if and employee was ever to challenge you on it.
It is not plausible to expect employees to work that many hours. Just the liability of exhausted employees on the road should be enough to make you change your ways. Believe me you will reevaluate when you have a tragedy occur because of your business practices.
We work 4-10's and only do that because working 2 more hours when its 110 is better than getting up to 90 degrees at 4:30 AM for another day's work. I have also found if I want to keep my clients happy with prompt response time to extras and improvements and keep my employees from burning out I need to have one extra employee for every 3-4 that I have booked for work. I have found that invariably as mentioned above someones child will be sick, an car will break, a forgotten appointment will pop up something will happen to disrupt my finely tuned schedule. Better to have extra manpower on staff than putting undue pressure on your best guys, the ones that did show up. A happy employee is a safe and good employee and you can't expect anyone to be happy for long if they are working 15 plus hours a day.
I can hear it now, what do I do with that guy if nothing pops up or I have no extras?
Like that will happen. The best part is you will find you will make more money because your not paying O/T and you can bill out for more. Your guys will get more done in the first 8 hours than they will in the second 8 so your production rate will go up as well.