Finding floor joists is the key to fixing a squeaky floor.
It's the middle of the night and the tranquility of peaceful sleep is interrupted by an irritating "SQUEEEEEK." It's that darned floor. Someone in the house if up and around, but now everyone's awake. Often caused by years of contraction in dry winters and expansion in humid summers, a squeaky floor can be an ongoing source of frustration.
The problem may lie either with individual floorboards or the subfloor. If the squeak occurs only when pressure is exerted on one or two boards, then the problem is probably with those boards. Try applying liquid wax, talcum powder, or powdered graphite in the groove between the boards to lessen the friction and quiet the squeak.
If that doesn't do the trick, drill small pilot holes near both edges of the boards where they are squeaking. Drive two-inch finishing nails through the pilot holes and into the supporting tongue-and-groove structure, securing the boards together. Set the nail and fill in with matching wood putty or wax.
If the squeaking occurs over a broader surface that is one or two feet wide, the likely culprit is movement of the subfloor and the solution is to reattach it to the supporting floor joists. One traditional approach would be to expose the joists from below and make the repair. However, if the problem is on an upper floor, the associated mess and ceiling repair make this a very unappealing option. A better alternative would be to take a top-down approach.
First, the floor joists must be accurately located, a job that requires the proper tool. While there are several stud finders on the market today, most cannot find a joist through hardwood flooring or reach the depth required. One that will accomplish the job easily and quickly is Zircon's MultiScanner® i520 OneStep® stud finder, which can locate joists up to an inch and a half below the surface. Moreover, beyond locating the edge of the joist, it will project a beam of light over the stud center, pinpointing the best possible location for fixing the problem.
Once the joist is located, bore an angled pilot hole through the flooring, the subfloor, and into the joist. Drive a 2 1/2 inch finish nail through the floor and into the joist. Set the nail and fill in with matching wood putty.
