Before signing a home repair contract you must do your homework. Do some research and make sure your contractor is licensed and bonded by the state and local community.
Before signing your contract read it thoroughly and make sure all the terms and conditions that you agreed to are in it and nothing has been added or taken away. Never pay the full price of the home repair upfront. Put down a reasonable down payment with the remainder of the balance due when the job is finished this is to protect you from unscrupulous contractors.
An example of this recently I had a new air conditioner unit installed in my home the contract detailed exactly what I wanted such as the size of the unit and what extras had to be done to install it I placed a reasonable down payment and paid the balance in full when the job was complete everything went well and the job was finished in three days to my complete satisfaction. This is why it's so important to deal with a reputable contractor. When dealing with this type of contract just use plain common sense you don't have to be a legal genus.