My old boss in Tulsa would not let us put a level on stair stringers, and he was right
We cut 14 stringers for a deck rebuild last month and the new guy kept checking them with a 4 foot level instead of just trusting the rise over run math. Every one came out off by a quarter inch at the bottom step, and we had to recut three of them, which cost us about half a day and two boards. Does anyone else measure their stringers with a framing square and stair gauges, or am I just stubborn about it?