4. "Check my references."

Indeed, you want to hear this. But you should understand that sleazy contractors can easily supply the names and phone numbers of buddies to give bogus praise. What you want — and will get, from legit workmen — are the names of past local customers, neighbors whose homes can be visited to check their work.

It's also smart to check the local courthouse and your state's contractor licensing board, asking about any current or past lawsuits against the contractor. You'll also want a copy of the contractor's license.

Other calls worth making: Your town's building inspector, who may only be allowed to verify a workman's credentials. Saying nothing may be code for "pass on this guy."

Or try specialty lumber yards and plumbing and electrical supply stores where reputable contractors are likely to be known.

5. "We have a special limited-time offer."

This mantra is common among summertime door-to-door salesmen who claim to represent home improvement companies. And sometimes they do. But any legitimate offer for today should be honored in coming weeks, after you've had a chance to shop around and check references.

6. "I have leftover materials from another job."

His leftovers, his problem — but hiring him could be yours. At best, assume this phrase means the contractor is inexperienced or incompetent for not accurately estimating what was needed for the earlier job. And what does that say about the price he'll quote for yours?

You should suspect that, at worst, he purposely cheated the last customer by overbuying, never finished the job or is just cruising neighborhoods looking for "act now" patsies who believe that unused two-by-fours or roof shingles will spoil on the back of his truck. Don't be one of them.

Also of interest: 3 reasons why older adults may fall for scams. >>

Sid Kirchheimer is the author of Scam-Proof Your Life, published by AARP Books/Sterling.