From a legal standpoint, what you want is an addendum, kind of a second contract that is added on to the first.
It doesn't have to be fancy, but it does have to be good English.
The opening paragraph should state that it is an addendum to the original contract and i the event that any statements conflict between the two documents this addendum should be considered the final version. After that, go wild ! Ask for the sun, the moon and the stars.
It might take several sit down talks before both side agree.
- Change payment plan to something you feel more comfortable with. Perhaps you should buy the material and have it delivered to the job site. A written material list is yet another document.
- The more payments the better, but you need to be specific as to what work needs to be completed for each payment.
- It there are any "change requests" including additional material, that is yet another addendum/negotiation.
- Start dates need to be specified. Perhaps a penalty for not starting on time ($100/day ?).
- Completion dates for each payment need to be specified along with penalties.
- When specifying the above, you can add "... or as mutually agreed upon" so that it the guy has some kind of emergency you can give him some slack.
- Anything that was VERBALLY stated before, needs to be in WRITING in the addendum.
Keep is simple and easy to read. People understand bullet point like I just used. The addendum needs to be signed by both parties and both parties need to have a copy.
My son asked my to review the contract for his new roof. The addendum was about a page long. Most of it was written down statement of what the salesperson (owner) stated they would do (1/2" OSB instead of 7/16", panel clips every 2 feet when not backed by structure, etc. etc.).
Last and most important,
IT IS UP TO YOU TO ENFORCE THIS ! If you can't be on site, you may have to hire an inspector. A friend did this on his home build
(over $200k). The inspector had the blueprints and would do a walk through every day or so after the crews had left. He caught several major framing errors
(windows in the wrong place, etc.) that never would have been corrected once the electrical/plumbing and drywall was installed.
At my son's job site the delivery truck showed up with 7/16" OSB. I told them NOT to unload it and then I called the company. They were not happy and had to do some quick work
(and likely pay a premium price) to get 1/2" OSB delivered, but it happened.
The other thing I did is make some copies of the addendum signed by the salesperson and I handed them out to the job site foreman. Nothing was really out of the ordinary, but he reviewed it and reviewed with other key job individuals.
Walking around with a camera and actually climbing up the ladder to snap some pictures, proved I was serious ! The job went very well !
Again, you have to be prepared to stop the work and delay completion of the overall job it a step is not completed to YOUR SATISFACTION !
Back at my friends job site, he canceled the closing twice because the "punch list" was not completed. The mortgage company backed him 100%. The third time the builder actually did a walk through with him a day or two before and review the punch list on site.
IN THE END, NO ONE IS GOING TO COVER YOUR *** EXCEPT YOU !