September, 2006
Inspection News and Views from the American Society of Home Inspectors

Creaky Floors and Other Issues That Bug Homeowners


Sometimes clients are bothered by conditions that don’t qualify as defects, but, nevertheless, are important to them. ASHI Member Jim Rooney answers questions about both defects and bothersome conditions in his Q&A newspaper column, and has granted the ASHI Reporter permission to reprint those columns. Here’s how he answered questions about two annoying conditions.

Q: Our house was built in the mid-60s and has oak floors. We had them refinished several years ago, and they still look great. However, they have always creaked. Do you have any ideas on how we can stop the noise. I am handy with home jobs, and a friend suggested I install some wood screws (sheet metal pan heads) from the underside in the basement through the sub-flooring into the oak planking. Mostly the noise is in the hallway— rancher-style house— and bedrooms. Any suggestion?

A: Noisy floors are high on the house complaint list and the building industry has produced dozens of products over the last generation to combat the problem during construction, but your house probably predates most of them.

Hardwood floors tend to squeak over time and the newer pneumatic nailers don’t seem to pull the boards together as tightly as the old-fashioned maul-nailers did during installation. Old houses with hand-nailed hardwood are very creaky when you walk across the floors. My mother used to say that they kept people honest. I didn’t know then how to quiet them down. I do now.

Your squeaks are created when the nail holding down the flooring strip loses its grip, and the floor pulls up and down a bit under foot traffic. It occurs more as the house dries out with age and the nails loose their grip. When you walk over a piece of loose flooring, the nail slides back into its hole, causing a squeak; as you remove your weight, the nail pulls back out, causing another squeak–like a dissonant violin bow over a string. Many hardwood floors will quiet down after refinishing, as the finish seeps between the strips of flooring, acting like glue. Since yours didn’t, it must be pretty loose.

You are in luck because you have access to the joists and sub-floor from the basement below. In the old days, folks would go down into the basement with shims, try to locate the squeak and then shim up the sheathing board under the loose oak at the location of the squeak to quiet it down. Sometimes it worked, sometimes it didn’t.

Your friend who suggested screws was on the right track. You’ll need a fistful of inch-and-a-quarter drywall screws and an electric screw gun.

Have a helper walk over the floor while you are in the basement, and try to locate by ear the approximate area of the squeak. Then, take a drywall screw and run it up through the sub-floor–which, at your house, will probably be half-inch plywood–and into the underside of the oak wood flooring. You are trying to pull the floor down to the sub-floor, but just stabilizing the sub-floor and oak floor at the shaft of the screw may be enough to silence the squeak.

The oak flooring will be hard as a rock, so expect to snap a screw or two on the way in. You’ll soon see why the electric screw gun is so important. Hand screwing into oak working overhead is torture. Don’t worry about broken screws–they don’t hurt anything and trying to extract them is a wasted exercise. Drag the side of the screw through a bar of soap or some paraffin as a lubricant to reduce the screw snapping, but if that doesn’t work, driving a tiny pilot hole prior to trying the screw might do the trick. Use the smallest drill bit you can find because if the pilot hole is too big, then the screw is useless.

The only thing you can really do wrong with this approach is to over-drive the screw or use a screw too long for the job. If you do either, the screw points will protrude from the surface of the finished floor, and that’s dangerous. Also, with the screw points lying just below the surface of the floor, the next floor sander will use your name in vain as he ruins sanding belt after sanding belt as the screw points rip through the belts as the sanding lowers the surface, exposing the screws.

Quieting squeaky floors is infinitely more difficult on noisy second-floor hardwood, so count your blessings that you have a one-story rancher. When you can’t get to the sub-floor because there is a finished ceiling in the way, you have to resort to going into the hardwood from the top. Doing that properly requires a counter-sink for the screws so the heads will set about 3/16ths of an inch below the floor surface and a plug cutter that is the size of the counter-sink so you can— with a drill press— cut hardwood plugs from a scrap piece of flooring to put into the screw holes. The plugs are glued-set into the screw holes, with the grain running parallel to the floor’s grain. Then, the plugs need to be cut off at the floor level, sanded and finished to blend into the floor to finish the job. Most leave that to the pros. When it’s done right, the plugs disappear.

Q: My bungalow house was built in 1959. It had three inches of loose blown-in insulation in the attic. Several years later, I put rolls of four-inch paper-backed fiberglass insulation on top of that. I did not staple it to the rafters. Everything is still OK up there. I know I need more insulation. Can I put some R-19, or better–not paper-backed, on top of that? I’ve been reading your articles for a long time and trust your answers. Also, should the eaves in the attic be covered? Mine are.

A: There are some basics we need to go over before you decide what and how to proceed with your insulation plans.

Think of your living space as a box that ends just at the other side of the floor, walls and ceilings. That is the space in which you want to keep conditioned or warmed air. In the construction world, that’s called the building envelope. The attic air space is above the building envelope, and is merely an enclosed area that happens to be the size that it is as a consequence of the way the roof is framed. The roof’s only job is to keep rain and snow off you. It doesn’t need or want heating or cooling.

Insulation is the stuff we use to try to keep as much of that hard-earned heat inside the house where we can benefit from it. Your original three inches of blown insulation from 1959 has probably settled flat on the rear of the ceiling drywall and has a marginal insulation quality remaining, so you were wise in going over it with the nominal four inches of rolled fiberglass. That insulation was intended as wall insulation and has an R-value of 11. But unless you were able to place it side by side almost air tight, your coverage was probably only in the high 80 percent range, and, although better than no insulation at all, was still pretty heat-leaky. The kraft paper backing on the four-inch rolled insulation has traditionally been called a vapor barrier, but it’s really not–all it ever did was provide a surface upon which the batt insulation could be glued and it made the product much easier to install. Foil backing does act as a barrier–a whole other subject.

Some might tell you that you’ll have to remove the four-inch layer of insulation before adding more insulation over it because the paper backing could be a condensation plane and cause you problems. If it’s kraft paper only–not foil–then I wouldn’t worry about it.  

I presume you are planning to add the additional layer of insulation yourself. You also say you are going to use unfaced batts. That means you’ll buy bags of R-19 fiberglass insulation that, when opened, sections of six-inch insulation without any paper on it will pop out, and you can handle them in about three-foot sections. They are normally 14-1/2 inches wide and are designed to fit tightly between the ceiling joists. You may be able to do this with just what you have up there, but if not, then lay them perpendicular to the joists and tightly, side by side and end to end. Obviously, work from the outside in toward the access to the attic so you don’t paint yourself into a corner. If the ventilation of the attic is by louvers at the attic ends, it really doesn’t make that much difference if some overhangs the eaves, but it does make a difference if any touches the underside of the roof as it slants down towards the eave. Insulation in contact with the under-roof can lead to condensation and cause roof rot there. If you have had roof-ridge ventilation installed sometime over the life of this house, then the eaves must be kept clear.

They manufacture foam plastic baffles that you install at the roof edge to keep the eave space open and prevent the insulation from coming in contact with the underside of the roof.  

Now is the time to do this job because although there is no time during which working in an attic is fun–it’s a whole lot more tolerable when it’s cool or warm up there rather than 130º degrees or freezing. Also, when handling fiberglass insulation, wear old, long-sleeve shirts and wrap your wrists with tape and wear goggles, a good respirator and a hat as the stuff launches small glass fibers that itch and annoy. Take off these clothes when you are done and pitch them because if you run them through the clothes washer, they can leave glass bits in the machine, only to be deposited on other clothes during the next load.

To reach Jim Rooney, write “On The Level,” c/o The Capital, P.O. Box 3407, Annapolis, MD 21403.