Our house has beat-up hardwood floors covered by wall-to-wall carpets. The floors squeak badly. Is there any way to fix this problem from the basement, without removing the carpeting?
Squeaking floors can be very tricky to repair, but if you can work from underneath the floor you have an advantage. The squeaks are often caused by floor boards rubbing against nails or each other, or the floor joists, because they are not securely fastened.
A repair method that sometimes works is to check the underside of the floor for gaps between the subfloor and floor joists. The gaps must be closed to prevent movement using thin wood shims. Have someone walk on the floor while you check underneath for places that squeak. When you pinpoint a squeak, and find a gap, spread some glue on both sides of a shim and tap it firmly into the gap.
Special screw-on brackets are also available for use from underneath on squeaky floors. One leg of the right-angle bracket is screwed to the joist; the other is screwed into the floor to pull loose flooring together. It is also possible to stop some squeaks from above, right through carpeting. This requires use of a special installation tool and special screws that break off when properly inserted so the heads are not visible.