A.Tandy Reeves, a certified flooring inspector and CEO of Flooring Inspection Training Services in Tulsa, Okla., responds: Unless you have access to the floor joists and subfloor from underneath, the best approach is to pull back the carpet and cushion to see where you're putting the screws or nails. That way, you'll be able to verify that you're securely fastening the subfloor to the floor joists and eliminating the squeaks. After making the repairs, have an installer put the carpet back properly; reinstallation is not very expensive.

Where there is access to the floor system from underneath, you should be able to locate the squeaky area and correct the problem with strategically applied shims or blocking and construction adhesive.

Keep in mind that there may be finished flooring covered by underlayment beneath the carpeting, and the squeaking may be the result of movement between these layers of wood. In that case, hitting the joists wouldn't be critical, so fastening through the carpet might be an option.

I wouldn't use screws, though; unless a screw runs all the way through the carpet and cushion and countersinks itself, it could create a dimple in the carpeting as well as a screw head to step on. And if the screw should grab some of the carpet, primary backing, or secondary backing, it could pull and distort the carpet in that area. Instead, use pneumatically driven ring-shank nails, which provide the most holding power but are less likely to damage the carpet.