Squeaky floors are very common in older homes. Wood floors squeak when something—usually a board—works loose and rubs against another board or against the subfloor. You can de-squeak the floor by either lubricating between surfaces that rub to reduce the friction or by stopping the movement altogether.
Lubricating is easy but not always effective. Try working a little powdered or liquid graphite or talcum powder between floor boards and then clean up the surface.
Stopping the movement is a more permanent solution. To determine exactly what is squeaking, go under the floor, to a basement without a finished ceiling or to a crawlspace, and then listen while somebody walks above you. If necessary to locate the squeak, remove any insulation.
Check for nails that have missed the floor joists and are rubbing up against them, causing the squeak. If you find these types of nails, cut them off with a good pair of diagonal cutters.
Also check for areas where the subfloor may not be nailed down with enough nails. If there is a gap between a joist and the subflooring, drive a glue-coated shingle or shim between the joist and subfloor just tight enough to kill the squeak. If that doesn’t work, drive a screw through the subfloor into the underside of the surface flooring. Be sure the screw is short enough not to pop through the surface. Insert it through a fender washer before driving it. It’s easiest to use square-drive or drywall screws and a power screwdriver or cordless drill with the appropriate tip.
Squeaks coming from between joists may be caused by inadequate bridging. Renail any loose planks and, if necessary, install a reinforcing piece of bridging against the subfloor, as shown at right. Nailing solid blocking between floor joists can also strengthen the support for subflooring, eliminating squeaks. If the joist is sagging and the subfloor is flat, cut a piece of 2-by-4 long enough to extend 12 inches beyond the gap on either side. Nail it to one side of the joist.
Finish flooring that does not fit flush with the subfloor can be tightened from below. Drill a couple of 1/4-inch holes through the subfloor, taking care not to drill through the finish floor.
Press the nozzle of a carpenter’s glue bottle into the holes and force glue up into the space between subfloor and finish flooring. Then have someone stand on the raised spot while you drive screws through the subfloor into the finish floor. Be sure the screws are long enough to grip the finish floor without going all the way through, and use washers to ensure the screws will not be pulled into the subfloor.
Another method is to pre-drill pieces of 2 by 2, 18 inches long, at convenient angles for driving 2-inch or 2 1/2-inch screws into the subfloor and joists. Partially drive the screws into the pre-drilled holes. Coat the screws with carpenter’s glue and power-drive them into place.
If you can’t get under the floor, or the underside is covered with a finished ceiling, try squirting wood glue into cracks between boards and working it in with a putty knife. Wipe up the excess glue and weight down the surface.
As a last resort, drive ring-shank nails at a slight angle into floor joists, as shown at left. Before driving them, drill pilot holes so that the wood does not split. Use a nailset to sink the heads below the wood’s surface. (If you re-sand the floor in the future, these nailheads can be troublesome because they may tear up the sandpaper on the power sander.) Fill the nail holes with wood putty colored to match the flooring.