Hardwood floors are a stylish and warm addition to any home. However, over time, some floorboards could start to squeak when you walk over them. This occurs when there is excess movement in the floorboards, usually because of a gap between the board and the joist below. If you're a do-it-yourselfer, you can eliminate those gaps and stop the squeaks once and for all.
Walk into the basement or crawl space, and have a helper stay on the ground floor.
Walk across the floor along each row of floorboards systematically, having your helper walk. When your helper hears a squeak, he should knock on the floorboard so you can detect the position of the squeak down below.
Apply the carpenter's glue to a thin wood shim, and slide it in between the joist and the flooring where the squeak is occurring. Gently tap it in with a hammer until the gap between the joint and floor is eliminated, but don't force it in so far that the flooring starts to raise up.
Secure the shim in place by driving a a 1¼-inch drywall screw through the joist and shim into the subfloor with the power drill, at a 45-degree angle.
Repeat steps 2 to 4 until you and your helper have checked the entire floor and repaired any squeaks. Have your helper do a walk-through one last time to check for missed squeaks.