The flooring contractor that installed my flooring left 30 holes (1.25" diameter; .25" deep) in the wooden stair skirt of my staircase without any prior notice that I would have to get these fixed. He threatened me with a pre - lien and I sent him the final payment (certified mail) - which I believe, never reached him and is being returned by the USPS. In order to ensure I'm fully protected, I'd like to know if I have to have the contractors employees and vendors complete lien waivers for amounts already paid and then have the owner do a Final lien waiver form when I provide the last payment (again) - EVEN I have to hire someone else to patch the holes he left in my walls. How can I make sure I'm protected?