How do I write a waiver/release of liability for an uninsured contractor?

I am going to hire a contractor to install hardwood floors. However, his company does not have any workers comp insurance. In order to avoid liability of injury, disability, and death, I guess that I need a waiver/release of liability. He will bring 1 to 2 persons to my home to do the job. I do not know the relationship between him and other people. It can be employer-employee, partner-partner, or contractor-subcontractor. To minimize my liability, which combination of the following waivers do I need? 1. His company 2. Himself 3. Any other person that will come to my home to do the work 4. His company and everyone that will come to my home to do the work Please give answers for 3 different relationships. If there is a better way to construct the waivers, please let me know. Thanks.