our floors are starting to squeak
15 January 2005
A. Noisy floors are one of the most common new house complaints and the building industry has produced a myriad of products in the last ten or fifteen years to combat the problem during construction but donít appear to have worked for you.
Hardwood floors are not immune to squeaking and the newer pneumatic nailers don't pull the boards together as tightly as the hand operated maul-nailers did during installation. Old houses with hand nailed hardwood are very creaky when you walk across the floors and my mother used to say that they kept people honest. By the time we were teenagers we had all the creaks in the stairs of our 1920s house memorized so that we could climb the stairs silently in the dark. I didn't know then how to quiet them down. I do now.
Your squeaks are created when the nail holding the subfloor down on the floor joist loses its grip and the subfloor pulls up a bit. It occurs seemingly more often as the house dries out with age and more nails loose their grip. When you walk over a piece of loose subfloor the nail slides back into its hole, causing a squeak, and, as you remove your weight, the nail pulls back out causing another squeak-- like a dissonant violin bow over a string.
You are in luck being able to access the joists and subfloor from the basement below. In the old days, folks would go down into the basement with shims and try to locate the squeak and then shim the board permanently up at the point of the squeak to quiet it down. I've got a quicker solution. Using construction adhesive, the type that comes in a caulk tube, you merely lay a bead of adhesive like a bead of caulk between the subfloor and the joist and as soon as it sets up it will permanently and solidly glue the offending subfloor quietly to the joist.
The second floor is a little more difficult but not impossible. You are going to use screws to screw the subfloor down to the joists to quiet them down. They make screws specially designed to be run through carpet then through the subfloor and into the joist whereupon they are designed to snap off flush with the top of the subfloor so there is no exposed head left. Great idea but we can create our own variation on that theme and save some money and time.
You'll need a fistful of inch and quarter drywall screws, a couple of 10d finish nails-- they are two and a half inches long-- an awl, a hammer and an electric screw gun.
Dance around the subfloor and isolate the area of the squeak. Assuming that the floor joists are running from the front to the back of the house on 16 inch centers, try to locate the nearest joist. If you can pull the carpet up to look, that's great because then you can observe the heads of the subfloor nails telling you exactly where the joists are but if you must leave the carpet in place it's a little harder.
Tap on the floor with the hammer in a line perpendicular to the way the joists are running. When the sound goes from hollow to not so hollow then you are probably over a joist. Take the hammer and a finish nail and drive the nail down through the carpet and floor. A finish nail has a thinner shaft than a common nail so it'll be easier to drive and will leave less of a hole. You'll know if you've hit a joist because the nail will remain stiff as you drive it. If you missed, the nail goes in quite easily once it has passed through the plywood subfloor. Move over an inch at a time probing with the nail until you've found the joist.
Once you've found the joist pull the nail out and widen the hole in the carpet backing with an awl so that the head of the drywall screw will fit through, then take the screw gun and drive the drywall screw down flush with the top of the subfloor. Repeat this process until the squeaks are gone then carefully refluff the bits of carpet where you've been working to disguise the effort. Quieting of squeaky floors is possible but infinitely more difficult on noisy hardwood so count your blessings-- it could be a lot worse.