I finally fixed the squeak in my stairs after 4 months of guessing wrong
Back in March I noticed a squeak on the 4th step going up, so I figured it was just a loose tread and screwed it down from above. That did nothing. Then I tried shimming under the tread from below, which meant crawling into a 2 foot crawlspace with a flashlight in my teeth, and it still squeaked. I ripped out the whole tread after that, found the real problem was a split in the stringer where a nail had been driven in at a bad angle years ago, and glued and clamped it back together. Total time from first squeak to silence was about 4 months of weekends, and 3 trips to the hardware store for stuff I didn't need. Turns out the whole fix took 40 minutes once I knew what I was looking at. Any of you got a trick for finding squeaks without tearing half the staircase apart?
A 4 month hunt for a squeak that was 40 minutes of real work is the most stair-fix story I have ever heard. Here is the angle nobody talks about: squeaks move. That 4th step squeak was really the stringer, and the stringer only made noise when weight shifted the whole run, so it came out sounding like step 4. I chased one for weeks on a landing that turned out to be the rim joist under a wall two rooms over. Next time, walk the stairs with one foot near the wall and one near the rail, then switch. Whichever spot changes the sound tells you which side carries the load. It also helps to have someone else walk while you press your ear to the skirt board, since you feel the vibration before you hear it.