I ignored the tack strip gap rule for 3 years until a staircase in Tulsa humbled me
I always left a quarter inch between tack strip and the wall because that's how the guy who trained me did it, figured it was just how it goes. Then a customer in Tulsa called me back twice about her stairs feeling loose at the top, and I could not figure out why. A 30 year installer named Ray rode with me on the third trip and pulled the strip back, showed me the gap was letting the pad shift every time someone stepped on the nose. He runs the strip tight to the wall on stairs and uses a stair tool to tuck it, and those steps have not moved since. Now I check that gap on every staircase before I even cut pad, it takes 10 seconds. Any of you run into callbacks that traced back to something your trainer just did without explaining why?