I think if you're going to air dry it, quarter sawing makes a huge difference. All of the pieces I had that weren't, moved quite predictably with the growth rings. But the more vertical grain pieces stayed nice and flat. How soon did you use it after bringing it inside the shop? Mine ended up pretty dry after spending the winter in the basement - much drier than the stuff they try to sell as "kiln dried" at the big box stores.
I think it was around 12-14% by the time I started cutting into it. Come to think of it, most of the movement was in the winter when the house dried some. Yep, 1/4 sawing it would have been ideal, but the guy that milled the boards was looking for a quick turn around. It still took us about 3 weeks to get it all done working 1/2 time. nate, yeah, they made it look so easy on tv. To top it off, it only took 1/2 hour. I still watch old Norm episodes and have a bunch of 'em, but I know what it takes to build that stuff now. My younger brother and I had a little shop for a while, and all we really had was an old Craftsman TS, a router, my Craftsman RAS and some other stuff. We did pretty good work. Anyway, back to the wormy staircase.
