Friends, are you troubled by squeaky floors? Well-el-ell, try the amazing "Squeak-no-More" system. One of my clients is a single college professor who is building his empire in part on renting out rooms in his house. He's a character, a likeable guy from Italy. He has a new tenant in the large semi-apt. on his basement floor. He likes the guy, wants to keep him but the fellow has been complaining about loud squeaks in the hardwood floor above his unit. One spot in the main route of foot traffic was particularly bad.

My client found the product in a web search and asked if I could make it work. I'm happy to say I did get it to work, as it makes me look good. Wasn't that hard to use. It's an ingenious system. Uses square drive 3" screws, the bottom inch has 7 threads per inch, the next inch has 8 threads per inch, and the top inch starts with a score all around just above the second batch of threads with bare shank above that. It has a hard plastic collar device that you run the screw through, at least when you're above a joist. You pre-drill a 1/8th hole, when the 7 TPI section hits the joist, it wants to move faster than the 8 TPI section which by then is in the floor board. This draws the two together, and shortly after the 8 TPI section enters the joist somewhat, locking the two together, the screw head reaches the stop in the collar which makes the thread snap at the scored part about a quarter inch below the surface. Looks just like another nail hole to fill.

It worked especially well on my client's floor as it's the older face nailed style. In a T&G set up, you'd have holes where there been none but oh well, it's that or the squeak. Good filling will make them disappear well enough. I use the wax crayon like filler sticks as no sanding is needed.

It also worked on the sections with no joist - the face nailed rows were every 8 inches - half above a joist and half not. You use a different technique for those, a jig tells you when you're at the proper height and you then snap it off by wiggling it back and forth. Doesn't have sufficient grab to snap the head off with torque. Finding the joists is a big part of making this work.

Also works under carpet, some extra techniques used to keep the drill and screw from grabbing and twisting the carpet. You just wrap them in scotch tape which stays intact until it hits the wood.

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1986 300SDL, 362K
1984 300D, 138K

I've renovated a number of houses and have been using these for years. They work well and yes the tape around the shank trick works well (so does a piece of surgical tubing). Cut a small slip in the carpet and drive the screw and then shoot some carpet adhesive ubnder the edges and you are golden. On exposed floors, I would take a piece of sacrified flooring and snad it down and mix the sawdust with clear Elmers wood glue and fill the visible hole. Works like magic.

If you have issues with delamination of a double layer sub floor , you can drill small holes and inject a good wood glue inbetween the layers with a home built pressure driven syringe (5 gal water bottle glued shut and a scrader valve installed in the top-air hose goes to the back end of a glue syringe and put a petcock in the air line and that will ensure the glue gets wher it is needed.)

Cool!

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I had a customer many years ago that made a product called "Silent Floor" if I remember the name correctly. It was basically a very strong beam made of wood products to use in place of simple 2 by lumber.

Of course this would only apply to a major renovation or a new build.

Oh, I remember the name now. It was TrussJoist. They were near Nactitoches, LA.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

My partner came across http://www.mcfeelys.com/ a few years back to help solve floor squeaks. The stuff is very reasonably priced and works great. It is exactly as the OP described.