Cool topic. Always nice to see what other collectors do for a living.
I have a Sub Contracting buisness. I specialize in Epoxy
and Urethane Waterproofing coatings. Mainly Parkades with some Wharehouse work. In the buisness we call it "membrane", hence my user name...

I also dabble in Concrete restoration. We remove old
broken, wornout, concrete from parkades and replace
it with new. It's a never ending cycle here due to the
Salt used in the winter. It corrodes the concrete in no time.
I've been in this buisness going on 20 years. I'm at the point now that I just supervise my guys and only get in the "dirt" when my knowlege and expertise is needed.
But this still means long days as the working "outdoor"
season here is short so we have to get as much done in a relatively short period of time.
Plus my wife works me like a dog when I'm at home, LOL