How do I make exposed wood stairs less squeaky?
There are special screws for squeaky wood floors. You drill a small pilot hole, drive in the special screw and the head of it breaks off. The screw pulls the offending pieces together eliminating the squeak. You will want to try to screw into the stringers for the best result. With the head broken off a small hole remains that can be filled. If you have large gaps between the treads and the risers you may want to get some wood glue in the gap prior to installing the screws.