1. Like an ethical dog breeder, a good contractor has a waitlist
Quality contractors are booked. Immediate availability is a red flag. If you need someone to begin next week, you will mostly attract shady or new firms.
Major red flag: most companies you contacted had a waitlist. Finally, you found one who can start next week. He may also apply more pressure on you and make more follow-up calls. So look for any sign of desperation.
9. While prices will vary sometimes considerable, the lowest bidder is a red flag holder