So, you have an old squeaky floor, and you want to fix it so that it doesn’t make that annoying sound every time you walk across it – but how do you fix old subfloor? The good news is, there’s a way to quick fix it. The bad news? This quick-fix solution will only hide the problem temporarily, though it may be cost-effective in the short term.
The quick way to fix bumpy or squeaky subfloor is to add insulation to the subfloor to dampen the noise. Although this may solve the problem temporarily, you’ll probably find that within a few months, the noise has come back again. Why? Because the gaps between the subfloor and the joist are what is causing the problem, and as the insulation compacts, the squeak will simply return.
What can you do about it? No, adding more insulation is not the solution. Instead, try the more labor-intensive option: shim the subfloor.
Fix Old Subfloor: Use a Shim
If at all possible – and this is the most pain-free way of fixing the subfloor problems – get underneath the floor to make the needed repairs. You don’t want to have to pull up floor from above to fix the noise, since that will result in unnecessary additional work. If the floor you’re fixing is over a basement or crawl space, which is likely when it comes to creaky flooring, go down there and get started on the repairs.
Using a second person upstairs, have them walk around on the floor and listen for where it creaks. When you hear a noise, have them walk or press on that spot until you find the exact location of the noise. Then, coat a thin wood shim with carpenter’s glue, and tap it into place between the subfloor and the joist – but very gently. If you tap the shim in too far, you’ll end up raising the flooring, which will cause entirely different problems.
The shim should simply fill in the space that’s above the joist – that is, the spot that has been allowing the creak to come from the floor as it gives under weight. To keep the shim in place and add support, you’ll want to drive a 1 and 1/4 inch drywall screw through into the subfloor, going through the joist and shim at an angle.
Another method of fixing old subfloors is to use a tool that’s specifically designed to get rid of squeaks, found at your local hardware store. In appearance, it is a threaded rod that is attached to a mounting plate, and there is also a steel bracket that has a squared-off hook at the end. Essentially, it’s designed to eliminate noise.
Installation is relatively simple: screw the mounting plate directly to the subfloor from underneath, using the four screws that should come with this item. It should be placed under the squeaking area – use a second person to help pinpoint the location – and then get the bracket over the threaded rod, hooking it onto the floor joist.
Make sure you have a nut handy, because you’ll need to place this onto the rod before tightening the unit with a wrench. This will draw the subfloor down against the joist securely, eliminating squeaks!