Tipping is one of the most awkward acts I know. I got a couple hardworking and considerate HVAC guys redoing our home (duct, furance replacement, etc.). Real hard working and doing it as if it's their home and explaining every step of the way to me. Professionals, no doubt. Is a tip insulting to a professional or would it be appreciated? They'll be finished around 2, reply in comments if you could. Thanks!
Got a poll up on hvac-talk.com and currently have 29/4 in favor so far.