The inspiration was to talk about insulation on this site, as we both have backgrounds installing insulation residentially and commercially. However as we were discussing some ideas for what to put in here, it occurred to us that we have seen an awful lot more than that and it seemed worth discussing much more than insulation.
When your livelihood is in this space, you spend a large amount of time with other contractors doing foundation work, painting, siding, carpentry, and every imaginable service that can be performed inside and outside a house. If you like meeting people and learning, you can gain an enormous amount of knowledge about all sorts of things.
We wound up making some notes and found we had several pages of stuff we found interesting, so decided to try to cover it all in here. As you might imagine installation installers are hardly technically competent, but thankfully we have grown kids that got us started and did some editing and correcting for us.