Go to the basement if the squeaking floor is on the first floor of your home. If the squeak is on the second floor, use a small jigsaw to cut out a section of the first floor ceiling to reveal the floorboards underneath the squeaky area.
Have a helper walk across the floor while you watch and listen from below to determine exactly where the squeak is coming from.
Coat a small wooden shim with a thin layer of wood glue. Use a hammer to gently tap the shim into the gap between the subfloor and the joist at the point where the floor is squeaking. Stop tapping as soon as the shim is firmly in place. Trying to force it farther could cause damage to the flooring.
Use an electric drill to drive a 1 1/4 inch screw diagonally through the floor joist, wooden shim and subflooring to ensure that the floor won’t come loose again.
Ask your helper to walk over the floor again to ensure that the squeak is gone.