When making home repairs, when do you hire a professional and when do you consider a weekend warrior?

I do as much as I can myself. There are some things that I don't know how to like heating and air, major electrical stuff.

Funny how living in the sticks AND having a loader, backhoe, auger, etc. encourages self immolation as you have to justify buying the stuff in the first place. I'm an engineer so keep within my personal capability both technical and safety wise. I don't roam around roofs anymore. So if it's major electrical, well, HVAC, etc., I call in the Pros from Dover. Regular electrical, plumbing, trim work, etc. I'll do. My summer project was a complete chicken coop, fenced yard, watering system, and electrical for winter heat. I used to have Oil Can Henry do oil changes. However it takes longer to go some place vs. doing it yourself, so I do it. That will change sooner vs. later given my age. I do feel it more after crawling around the garage floor. Anything that requires an artistic touch is definitely out of my league.

I pass on working on gas lines...and high voltage. I suppose if I have to pull a permit, I would consider a professional. Maybe we should start a new thread and poll the crowd for house repair tips.... there has to be master electricians, plumbers, and jobbers parole lurking around.