San Diego Housing Market News and Analysis

There is a very simple fix for this; there are screws specially designed that have a "double head", like a small head with an additional mushroom head on top. You simply drive the screw into the subfloor, then using a tool like a screwdriver, you break off the mushroom head of the screw, leaving the first head in the subfloor and under the carpet and you can't see it...simple fix! The screw is designed to break off and leave the rest of the screw in place. Good luck.

I have the same problem and have the above mentioned "simple fix" screws and tools. The problem is finding the joists which i have been unsuccessful at. I have a pretty good (new) stud finder with deep scan but its impossible to find the joists and this tool mentions that you must screw into the joists to secure the wood planks below the carpet, tightening up the subfloor and eliminating the squeak. Maybe im doing something wrong.

I would guess it is probably be worth doing. If I were a buyer, I would notice that for sure and be worried.

Taking up carpet and putting the same carpet back down isn't really all that costly for a professional installer.

Possible to get to it from underneath? Remove the drywall on the ceiling, put in glue and shim shingles. Maybe some johnson paste wax and a grease gun.

I imagine people not having success mostly where two sheets of sub-floor butt together. You probably figured this out already.You know which one is not a butt joint because it has fewer fasteners over the joist as indicated by the stud finder.

The original fasteners should have staggered spacing...one on one sheet then one on another down the line into the joist. If you are averaging the space between these rows of screws your fix screws are going in the gap between sheets. Good chance also the the sub-floor was not fit well in the first place and it's hard to hit the the joist. Use a thin nail first, hammer it in partially and get a feel for hitting a joist. Then pull it out and sink a screw if you have good wood. Try starting your screws a little wide,with an angle towards the center of the joist, keeping in mind you have two rows of fasteners one for each sheet.

From beneath you would probably sister up to the problem joists with lumber with some sub-floor adhesive on top of the new wood and then go back up and put a few screws in.

I think taking up the carpet and using new full head screw is the best fix unless the oringinal sub-floor intallation was so sloppy that you can't get both good plywood and good joist with a screw.

If you have a metal detector or can borrow one, it will help you locate where the floor joists are. You will be looking for where the previous nails were sunk into the flooring. You'll need to locate them as accurately as possible and mark them (ie; placing something on the spot). When you get several, you should see it forming a line. That line should be where the joist is. Spacing between joists is 12inches or 16inches, depending on size of joist. One has to realize though, that this may not be very successful in locating where the joist is because the squeak may be caused by the fact that the contractor missed the joist when nailing the floor. Normally they use ribbed nails when doing this. These nails don't back out and they are a royal @#$%@! to pull out if you have to. Stud finders use ultrasound, which the carpet will absorb. The 'hammer' technique mentioned below - kind of works through carpet.

The problem with this is;

Makes it harder to pull up the mat under the carpet if the carpet is going to be replaced

Leaves potentially sharp ends under the carpet, that you might step on

May leave the appearance of dimples in the carpet because the screw may end up compressing the mat under the carpet

If it is important, I would look at pulling up the carpet. In fact, if you have old carpet - replacing it will help you get a better price on the house. When the carpet is up, you will be able to see where the nails were placed. Stud finders should then work as well. You can also rap(not drive) the floor with the hammer. It will sound different when you are on top of a joist and the hammer will want to bounce back a bit.

I had to deal with this with a house we had to sell. The contractor missed the edges of the plywood vs floor joist AND didn't get the tongue and grove on the edges locked together (end gap). This was compounded with the floor spacing being 16" on center. Ended up putting 2x3s screwed parallel(sister'd) into the joists and then screwing down the loose end of the floor to the 2x3. The ends were fixed by crippling the floor joists at the gap with cut 4x4 posts fit between the joists and adding a short 2x4 cut and screwed into the floor joist to help support the 4x4 sections.