Find out how long the contractor's warranty lasts for the work done. A typical period is one year or more. The duration of the warranty is not as important as the contractor's intention to support the warranty. People who perform well often work outside of written contracts. Keep in mind that manufacturers provide warranties for products, and warranties often only apply if the contractor is "certified" to install the product.
Be sure to talk to your contract partner about compliance with the manufacturer's specifications required for product warranty.
The contractor should discuss your home improvement project with you in detail. Areas to discuss with your contractor include the color and type of product you plan to use, how to get a permit if needed, what the daily cleaning procedures are, and how the work will be paid for.
Past results and customer service
Find out how long the artist has been working. While a contractor who has been in business for a year or two can do an excellent job, it would be best to choose a contractor who has been in business for at least five years. The longer a contractor works, the more experience they have, which often means more options and a better finish for your roof.
Many of the best players have had to face complaints. Complaints aren't always bad, but the way the perpetrator handled them could be. Ask contractors how they have handled complaints in the past, or contact the Better Business Bureau to find out.