final payment - what to put on the back of the check

In submitting the last payment to the contractor (insurance proceeds for hail damage) What to put on the back of the check - Need to be guaranteed that all contractors were paid on my residence. He has had problems not paying subcontractors or individuals on other job sites. Just found this out. His backer has quite backing him. The job is completed except for a couple of rooms and we decided not to do them right away. However, I want to pay for everything except the two rooms that were not done. Just want to be protected that he has paid everyone that has been on our property. I want to avoid any possible leins. He says everyone has been paid on our property. I can't read the terms and conditions - it wouldn't open up. Thank you