Legal Question in Construction Law in Pennsylvania

Re: contract law

99% of what you need SHOULD be in your contract, or your contract is inadequate (i.e. - it sucks). Document, document, document during construction. Do an invoice and submit. If you don't get paid, you send a letter stating that there have been no complaints about the work that was done, so you expect full payment in 10 days. At 10 days, you send a letter saying you are sending to an attorney for collection, unless it is a small claims matter, in which case just file your self. Backcharges... you can cause $10,000 in damages while working on a $5,000 job, so if I understand your question, yes, you can be charged more than the contract amount. Contract properly, and document.