Squeaky stair cases can be annoying and troublesome. If you have access to the underside of a squeaky stair, you can make an easy, invisible and effective repair. It’s only slightly more difficult from above, and with the right fasteners and a crayon for cover-up, no one will notice the repair.
For squeaks at the nose of the tread, cut short lengths of 3/4-inch (2-cm) quarter-round molding, coat them with wood glue, and toenail them into the inside corner formed by the tread and riser (see A).
Alternatively, use Squeeeeek No More (for carpeted stairs) or Counter Snap (for hardwood stairs) fastening systems (see Tip). The trim screws in both systems break off just below the surface, leaving only a tiny hole, and Squeeeeek No More screws go right through the carpet without damaging it.