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Since the squeaky floor is above you and if you don't have any access to the underside of the floor your repair options may be limited. Determining the cause of the squeak is your first mission. All floor squeaks are caused by rubbing between different floor components. Examples are the edges of plywood or hardwood flooring rubbing together, the movement of the floor due to loose nails or even movement in your floor's "substructures" such as loose bridging or trusses. With any of these scenarios, you need to be able to either 1) tighten up the loose members or 2) lubricate the squeaky area.
Tightening up the floor is the preferred repair since it is more permanent. First, the squeaky area must be located. If there are visible nails that are loose, pound them in and then install additional nails or screws on either side of the loose one for additional support. Of course, you need to attach these fasteners into SOMETHING solid, such as a floor joist, for the repair to be effective. This can be the most difficult part if the flooring is tongue and groove hardwood, since the nailing is concealed. However, you can cheat and use a magnetic or electronic nail sensor to locate the nails.
Many floors have two layers... a plywood subfloor of one or two layers and then a layer of hardwood. These two layers can become separated and move against each other or against loose nails. They can be screwed back together by first applying weight to the squeaky area and then installing screws or nails through both layers to reattach them. Be prepared to do lots of nailing/screwing... even "the masters" have trouble stopping a squeak with the first fastener!
If there is carpet, you will have to roll it back. Though there are some products on the market that suggest you can locate the floor joists through carpet, I don't have confidence in this method.
If the floor is a covered with self-adhesive tiles, sheet linoleum or sheet vinyl, you may have no choice but to nail or screw through the floor covering. Lubrication... typically spraying powdered graphite into the cracks to make the movement more silent... can work in some circumstances but is hardly a permanent solution to squeaking. It can also be messy since graphite is black and can stain some surfaces. Other lubricants such as silicone spray can create a dangerously slippery floor and should be avoided for this use unless used under carpet. Of course, lubricants can cause staining in carpets if over-applied. Wipe off any excess lubricant from exposed surfaces to minimize this possibility.
There are also a number of repair methods IF and ONLY IF you have access to the underside of the floor. For example, if your ceiling is a suspended ceiling... square or oblong tiles laid into a metal gridwork... you can lift a tile or two to see whether you have access. If you do... or if you want more information on squeaky floors... visit the squeaky floor article at our website: https://www.naturalhandyman.com/iip/inffloor/infsqe.html
Thanks for the tip... I'll be sure to pass it on. In ways, a more practical answer than mine and DEFINITELY less expensive and labor-intensive!
I give credit to your carpet installer for his honesty, knowing that his job might be delayed while you do the repair. Some companies tell the homeowner to wait until after the new carpet is installed. Home repair myths never die; that squeaky floors can be repaired with the carpet in place is near the top of the list! It is usually a "fool's sport" in my opinion. Floor squeaks are caused by a number of factors and most repair methods require a clear view of the floor to be efficient and effective... especially when a floor has as many squeaks as you describe!
The only exception is if you have a clear view of the underside of the floor, such as a downstairs floor above a crawl space or unfinished basement. Then there are some techniques that can be used, such as installing blocking, using construction adhesive or angled screwing through the beams to pull the floor down. However, since 50% of floors don't have any access from underneath, I will address the three most common causes of floor squeaks and repair tips...
Squeak #1: The nails holding the plywood to the beams have loosened.
The noise is caused by movement of the plywood against the nails. Simply banging the nails back in may silence the squeak temporarily, but the most reliable solution is to first bang in the nails and then install a screw within an inch or so of each nail for added strength. Sometimes, the plywood or the beams have slightly bowed. This pressure will pull the nails back out over time, making the use of screws an absolute necessity. It is helpful to stand on the squeaky area to press it down while installing the screws.
Screwing down a floor can be both backbreaking and time consuming...
especially if the squeaks are widespread. At the least, you must use an electric
drill with a screwdriver bit. An electric screw gun designed for this purpose
would be a step up, since they have features making screw installation quicker
and more accurate. A third option... the fastest and least fatiguing... is to
buy or rent a self-feeding screw gun that uses strips of screws. They drive
screws almost as fast as you can place the tool against the floor! One such gun,
the Quikdrive can be seen online at:
For screwing down ©" plywood, 2" #6 drywall screws are quite adequate, though (if available) a heavier weight #8 subfloor screw is better. Either square drive or Phillips heads are fine, though square drive screws can be driven with more power and less slippage. I have used both with excellent results.
Squeak #2: The floor is flexing at seams and two plywood edges are rubbing against each other.
This can happen when two pieces of plywood were pressed too tightly together during installation OR if structural settling has caused pressure between the edges. Stepping on the seam can cause a squeak. You may lubricate the seam with silicone spray or graphite, but this is, at best, a temporary fix. The better solution is to simply open the joint up slightly with a circular saw or jig saw. Just a "saw kerf" (blade thickness) of space is all that is necessary to ease up the pressure! I prefer the circular saw because of the shallow depth of cut. The deeper cut of the jig saw could hit pipes or wiring that were not installed to current codes and are too close underneath to the floor! Once the cut is made and the squeak silenced you could put some subfloor adhesive (either with a caulking gun or force it in with a putty knife) into the crack. This will stabilize and seal the seam, further reducing movement. Not absolutely necessary but a nice finishing touch!
DO NOT use the sawing method along plywood edges directly over a beam! Instead, install additional screws to tighten up the floor. The "saw kerf" repair is strictly for squeaks originating in seams that extend between beams (perpendicular to the beam) with no support underneath.
Squeak #3: A mysterious hidden structural member is moving when the plywood is walked on.
This is the worst possible squeak and requires the most skill to repair. You have this one when you have screwed your little heart out and the squeak is still as strong as ever! Sometimes the squeaky sound seems to come from "everywhere and nowhere", making it difficult to locate. These squeaks are caused by movement in the underlying beam or truss and are repaired on a case-by-case basis depending on the type of movement. First, a section of floor must be removed to expose the beam or truss. Second, examine the beam or truss for looseness. Third, stop the movement by using a combination or nails, screws and/or construction adhesive. Finally, reinstall the cut-out section of floor.
Floor repair is a whole lesson in itself, so I will leave you here (for now) and pray that all your squeaks are little ones!