What can I do about a squeaky floor?

Q: I have a 40-year old home with wood plank strips on the top floor. For years the floors in the center hallway and two bedrooms have been squeaking. What can I do?

A: The sound you're hearing is the nails in your floor construction and wood rubbing together. The solution is to stop the rubbing movement. Your floors can be silenced, but it's a tedious job, requiring patience and a good ear. You'll also need some basic tools and spiral-shanked nails. Walk around on the floor from various directions and put Post-It Notes or some other easily removable marker on the spots that squeak.

Once you've identified those areas, step back and analyze the pattern. If it spells out the words "get out of the house," run away. If not, look to see if the squeaks are in a line or a particular area.

Sometimes they're really a structural weakness expressing itself, or a subfloor material, such as plywood, that has lifted from one of the floor joists. This can be silenced by wedging a tapered piece of wood into loose spaces between the floor, screwing instead of nailing the bridging from below, putting in solid bridging instead of cross-bridging (also below the floor), using a syringe and squirting wood glue into the suspected spaces, or (as a last resort) using finish nails in the floor from above carefully nailed into the floor joists (which are 16 inches apart and difficult to locate).

If the problem is the floor structure itself, then all the glue and screws you can find won't solve the problem (unless you can pile them high enough to support the floor). If you suspect that the floor structure is bowing downward, get a professional opinion from an architect or engineer.

If the pattern is random, locate the most precise point of the squeak you can and drill a pilot hole, using a drill and a bit that is the same diameter as the spiral-shanked nail. The hole should be drilled at an angle, not straight down, since a vertical nail will tend to loosen.