Q: We have hardwood floors that squeak badly. The basement under the floors is unfinished except for insulation in the ceiling. What can we do to quiet the awful noise?
As you might know, squeaking in wood floors is caused by wood rubbing against other wood or against nails. The best solution is to stabilize the floors so movement is stopped, and this can be difficult. In some cases, the supporting structure is not stable enough to keep the flooring and subflooring from flexing enough to make noise.
When this is the problem, the floor needs to be strengthened with support posts, bracing between joists or other means.
That said, an old but temporary treatment is to lubricate the floor by sprinkling baby powder on the noisy areas and sweeping it into gaps in the wood. Carefully clean up excess powder (it’s slippery).
To try for a more permanent solution, go into the basement and have someone walk on the floors overhead. When a noisy area is identified, mark it with duct tape, chalk or some other marker. You will then have to remove the insulation temporarily from between the joists in that area. Wear gloves, eye protection and a dust mask. Removing the insulation will expose the subfloor and joists.
When the person upstairs walks on the noisy area, look for movement in the subfloor (the subfloor is sometimes plywood, sometimes boards). There may be small gaps between the bottom of the subfloor and the top of the joists that can let the floor move and cause squeaks.
Shims (thin wood wedges) can be tapped snugly into the gaps to stop the movement and, hopefully, the noise. To keep the shims in place, use wood glue such as Titebond. Special bracket-type hardware can be used instead of shims to tighten subfloor gaps; one brand name is Squeak Ender.
Sometimes the gaps occur between the layer of hardwood flooring and the layer of subfloor – you can’t see them. To fix these gaps, screws can sometimes be driven up through the subfloor and into the finish flooring to pull the two layers together.
This is tricky, since you don’t want a screw to protrude through the finish flooring. Subfloors are generally 3/4 inch thick and solid hardwood finish flooring is sometimes the same thickness, but the thicknesses can vary.
If in doubt about the length of screw to use, the best bet is to have a flooring professional check the floor.
Screws and nails are also sometimes driven into hardwood floors from above in squeaky areas, the heads set slightly below the surface and concealed with wood putty that matches the flooring.
McClatchy-Tribune News Service