Q: I recently had wall-to-wall carpet replaced. A few floorboards weren't too solid, and I suggested nailing them. But the installer said there was no need because the pad and carpet would muffle any noise. Not so. When I walk on the carpet, I can feel the boards giving, and it sounds worse when I am sitting down and someone else walks across the room. Can I nail the boards through the carpet, and if so what kind of nails would I use? Or am I stuck? - William M.

A: We hope the installer who suggested you don't repair the loose subfloor isn't in the bridge-building business, too. Two specific issues need to be considered here: the irritating noise created by the loose boards and the relative integrity of the floor itself. If the major problem is the squeaking floor, it requires a simple repair that can be achieved by driving hot-dipped galvanized finish nails through the carpet, pad and subfloor and into the floor framing members (floor joists) in the vicinity of the noisy area.You'll want to be sure to use a nail punch to countersink the nail head slightly below the surface of the subfloor to avoid injury.

But if you're still noticing some give in the subfloor after installing the nails, you probably need to provide additional backing to nail the subfloor. This can be easy if the floor framing is accessible from below and won't require removal of the carpet. If the floor framing isn't accessible, the best way to solve the problem may be to pull back the carpet and pad in the area affected to repair or replace the damaged subfloor.

You can then reinstall the carpet. Contact a handyman or small-repair contractor if this sounds like a project you aren't prepared to tackle.

Q: My problem is unusual. For two weeks I have been hearing the constant sound of water running through the pipes day and night. I live in a 17-year-old duplex, and I had a plumber make a thorough inspection of the house just a few days ago. He checked faucets, toilets and sprinklers but was stumped. Even when the water supply to the house is turned off, there is still the sound of running water, although it's less loud. The sound is similar to when the sprinkler system is on. Any suggestions? - Mary C.

A: You might have had better luck if you'd called a clairvoyant. The fact that you're in a duplex complicates matters. The noise very likely is coming from plumbing pipes that are in the wall common with your dwelling or even from a pipe that traverses your residence servicing the dwelling next door.

One of the best ways to find a plumbing leak in your fresh-water system is by turning off all the faucets and fixtures in the house and using no water. Go out to the water meter that services your home and see whether it's registering any usage (you may need to wait an hour). If it does, you have a leak somewhere between your meter and the fixtures in your home. If so, call back the plumber and ask him to make a more thorough inspection of the water supply to see whether he can find the leak.

If you don't find any problem with the plumbing, this exercise should be performed on the residence common with yours.

Another way to find running water is by using a long, narrow screwdriver as a listening device. Place the metal side of the screwdriver against the pipes in several locations of your home and the handle against your ear. If you hear running water and none of the fixtures or faucets is in use, then you have isolated where the problem is. Your plumber can then make the proper repair.