Here in NJ it's pretty much the same. Repairs and maintenance are taxable and capital improvements are not. Yes, we have a form called "ST-8" which the customer is suppose to sign, but most panic and have to call their accountant before signing it. We, as contractors, have to pay sales tax on materials in NJ. If we itemize our repair bill we only have to tax the customer for the labor....technically speaking that is.
Andy