I started writing a post about that final push installing the stair treads, and I couldn't finish it, it was just too exhausting and boring! So instead here's a bunch of micro-posts.
I bruised my head on the mailbox while I was vacuuming under the sawhorses on the front porch. I feel like that is a very distinct flavor of chaos.
There's theoretically two orders you could install a stair tread and a riser (riser behind, or riser sitting-on), and I'd decided to do it one way and then it turned out the size of pieces would only support doing it the other way. So I threw a minor tizzy fit.
Anyway, it turned out for the best, because the slight bendiness of the risers would have made the first way look like complete garbage.
All our research said that with stair treads you use nails and glue (well, "construction adhesive") together. I hate glue (on account of it being the worst), but using nails alone is apparently not the move so I sucked it up.
Sam and several other people told us the glue to use was this substance called "Bostik's Best." Here's my review of it: I don't wish any particular misfortune on the families of the people who developed Bostik's Best. It is not complete bullshit.
Once everything was all cut and 100% ready to go, installing a riser and the stair tread above it involved seven cycles of handing different tools back and forth. It went like caulk gun -> brad nailer -> drill -> shopvac -> caulk gun -> nails and hammer -> nailpunch. And somewhere in there Ruth had to squeeze past me to go stand on the work-in-progress stair tread.
Putting a tiny invisible bevel on one side of a stair tread makes it easier to drop into place.
AS EVER with this sort of thing, the first stair we did had a bunch of bullshit extra complexities that weren't repeated anywhere else.
The only other bad one was the sixth step, because the left side was unsquare in a unique and unexpected way that almost made it come out visibly crooked. I had to cut a replacement sixth tread, then find a narrower stair above where I could re-use the cattywompus one.