Tooling included to find the joist from above the floor
As seen on "Ask This Old House"
The Squeeeeek No More Contractor Pack is designed for heavy use in stopping squeaks in carpeted, hardwood, and linoleum floors. It includes 500 screws, a heavy duty tripod zinc fixture for carpeted floors, a fixture for hardwood and linoleum floors, 2 driver bits, 7 joist finding screws, and complete instructions. *** We have updated our kit with a redesigned screw. At the tip the screw starts with 8 threads per inch. One inch from the tip it then switches to 9 threads per inch, continuing to the score. The changing pitch pulls the flooring down tight to the joist as it moves through the floor board into the joist. The Squeeeeek No More kit is designed to stop squeaks in carpeted floors from above the floor by going through the carpet. Find the joist using the tooling provided in the kit. Then place the tripod fixture over the joist and drive the scored screw through the fixture as far as the fixture will allow. Snap the head of the screw off. The screw snaps off at the score leaving the screw thread to secure the flooring to the joist stopping the squeak. Because the screw snapped at the score that was set below the floor, there is nothing to feel. Because the screw safely passes through carpet there is nothing to see. The smaller fixture is used for stopping squeaks in hardwood and linoleum floors. In hardwood floors, the key is to drill a pilot hole so the wood does not split. Once you drill a pilot hole, drive the screw through the fixture as far as it will allow. The screw will pull the flooring together tight then snap 1/4 inch below the flooring. Then, simply fill the hole with wood filler. In linoleum floors use an electric stud sensor to find the joist so the screw can go into the joist. Once you find the joist, drive the screw through the fixture as far as you can go. The screw will pull the flooring together tight then snap 1/4 inch below the flooring. The linoleum will expand back over the hole making it very hard to detect.