I own a commercial property and had approximately 60k worth of improvement done on it last year. There was no contract except for a signed proposal which includes only a general list of work to be done and total dollar amount. There is no clarification about time frame for work to be completed, expected payments, etc. Contractor used what appears to not be exterior grade hardware on my ADA railing on stairs and ramp. Within days of install the screws and strap begin rusting as its winter. I reported this to the contractor and he says he will fix it. He sends a guy who replaces only a handful of screws leaving the majority still rusting, along with the straps. I had told contractor for two months that the final payment would not be made until work was completed. Final invoice was sent out in January. I wrote a response again asking for proper materials to be used and then radio silence for 5 months. I again stated I would not pay until the work was completed (ie. exterior hardware used) and their response was to threaten to sue. My question is, what are the implied causes in this “contract”? Did they breech it for not finishing the work? Did I for non-payment? What obligation do either of us have here?