John's Sewer & Drain Cleaning, Inc.

This will be answered when you ask if all employees are licensed. The only way to obtain a legitimate tradesman's license is to be a legal or naturalized citizen of the US. The company may employ people in positions that don't require a license, however, so it's wise to inquire.

Though a standard question, it's important to ask. Most contractors will tell you how long they expect the job to take without you asking. If they don't volunteer that information, be sure to ask. It's also helpful to ask if that's a hard finish date, meaning that it's the definite finish date. If it's a soft finish date, it may be extended for any number of reasons.

You'll certainly want to ask them this. Steer clear of any company that is not insured in Massachusetts, because that means that any incidental damage they may do on your property will be a real hassle to recover compensation for. It is never wise to work with uninsured tradesmen of any kind. Most states also require that someone have insurance in order to be issued a trade license. If they say they're licensed but not insured, they're being less than truthful.

Always ask for references, and always check them. Keep in mind though that the only references you'll get are people who the contractor is certain will give him a good review. You'd also be well advised to check online review sources in Cambridge as well, which will give you a broader view of customer satisfaction for a given company.