Framing and Sub-Flooring - Squeaky Floors

I did some research on my flooring and I figure the reason for the sqeaking is that the sub flooring and the top flooring are probably spaced. The sub flooring measures 29/32" in thickness (says so on the wood). Does anybody know what the thickness of the top flooring is ? It's a regular Toll Bros type house (14 yrs old)and I'm sure most top floorings made of plywood have a certain thickness.

I'm trying to figure out what aize screw I need to join both floorings from below at the basement level. I'm going to insert the secrew underneath the sub flooring and I'm concerned if the screw is too long it will come up thru the rug and if it's too short won't tighten both floorings.

Any help would be appreciated. The house is 3200 sq ft

To hard to say. Do you have floor heat vents that you can remove to see the layers of flooring?

To hard to say. Do you have floor heat vents that you can remove to see the layers of flooring?



Got baseboard heat ....I'll try and see, but I think all the cuts are pretty tight so it''ll probably be difficult to tell, but I'll give it a shot.

So I guess there's no standard size the big homebuilders use in this case. I understand custom jobs, but a standard job I was guessing that they use 5/8" plywood. But who knows .... maybe 1/2" or 3/4".

Do you have a closet nearby that you can pull a corner of the carpet up to see what's underneith? You could drill a hole and gauge it that way also.

Do you have a closet nearby that you can pull a corner of the carpet up to see what's underneith? You could drill a hole and gauge it that way also.


You're brilliant ... why didn't I think of that. I don't have a closet but I can pull back the carpet at the tack strip a bit and find that spot in the basement and then just drill down to determine thickness.

Thanks .... I'm just starting to learn to do things around the house, so I'm a bit slow.

Most subflooring material is 23/32. This is basically 3/4". Usually there is not an underlayment on top of the subfloor at carpetted areas, just the 3/4" subfloor itself, at least in the few areas of the country that I have framed in. There are a few things that can cause squeaks. Subfloor not glued and/or nailed properly, heating ductwork(you have baseboard heat, shouldn't be this), joist hangers and steel beams.

Subfloor----it is best if you can pull back the carpet and pad so you can locate the joists and the use some 2" gold screwsa and run them into the subfloor and joist about every 6" in the area where the squeak is. If you don't want to pull back the carpet then locate the joists and use a 2" trim head screw and run it down thru the carpet in the same manner. The trim head screw has a smaller head on it and will be pulled thru the carpet basically leaving no trace.

Steel beam----when a steel beam is place under the joists there usually is a 2x member that has been glued to the top of the beam. The glue is the major holding agent here and sometimes the framer will use nails nailed into the edge of the 2x and then wrap them around the bottom of the top flange of the beam to hold the 2x in place while the glue dries. These nails can them rub against the steel as you walk across the floor. If this is the case then use a hammer or pry bar to pry the nails up and away from the beam and remove them if you can.

Joist hangers----if the joist hangers or mounted on a steel beam they can rub against the steel and cause a squeak. Use some type of material that you can wedge in between the hanger and the beam to stop the squeaking.

One more----if the squeak is near a wall then sometimes the wall may not be nailed down to the subflooring properly. locate the wall by running a 3
" screw down thru the floor next to the wall to locate it in the basement, then run some 2" screw from the basement into the subfloor and into the bottom plate of the wall to secure.

Good luck.

In my original post I said the subfloor was 29/32". That was wrong .... it was 23/32" like you say (typo).

I put drill bit down and noticed as you say there is only a 23/32" sub floor and no added flooring. Joists are so called silent floor wood joists.

I think what I will do is try to send those trim head screws you say that will twist right thru the carpet into the joists. The sqeaking is too far from the walls to start potentially messing up the carpet.

Finding the joists should be the hassle of this job ..... thanks

Actually ...... can't I just go into basement and use gold 2" screws and screw right up thru joist and into the subflooring ? This way there's no hassle with carpet at all, and finding my joists are simple.

C1, yes you can do that however you will get better holding power securing the plywood material into the joists. It will be more difficult to locate the joists from above but it will be a better fix. Go into the basement then have someone walk on the floor above you so you can try to isolate the area the squeak is coming from. It may only be one joist or a few. Then use a 1/8" bit in a drill and run it next to the joist up thru just the plywood. Then us a 2-3" nail, as small in diameter as you can get, and drive it up thru the carpet. Do this at each end of the joist where the squeak is. Make sure noone is standing in the area. This way you can hook a string on each nail and know where the joist is. Or try locating from above whichever you prefer. Try to get the black trim head screws. I have found that they are stronger and resist snapping heads.

One other thought. There may be some "shiners" that are causing this squeak. Shiners are nails that missed the joist. If they are rubbing on the edge of the joist that can cause a squeak. Good luck.

Squeak no More screws will go through the carpet and work very well. they are made specifically for your problem.