A retired framer showed me why my string lines keep sagging
I was setting up a deck layout out in Tulsa last month and an older guy walks over, watches me pull a string line, and just shakes his head. He said I was cranking the line tight like a guitar string, which pulls the posts out of plumb when you release it. He showed me his trick: pull it snug, then back off a quarter turn, and let the line do the measuring instead of fighting it. That hit different because I've been fighting saggy lines for years and blaming cheap string. I tested it on a 30 foot run and the difference was night and day, no more false readings on my tape. Anyone else ever had a stranger walk up and fix a habit you didn't even know was broken?
That "back off a quarter turn" part is what got me, because how do you know when a quarter turn is actually enough? I’ve pulled lines tight my whole career and always figured more tension meant more truth, but he’s basically saying the opposite, that the line needs some give to stay honest. Did he mention anything about how wind or humidity messes with that snug setting, or is it just feel from years of doing it? Seems like the kind of trick that only works if you already trust your hands more than your tools.