Subfloor squeaks

[Tackle Anything]

I'm new to Home Repair Forum. If there's a thread out there relevant to my question, please let me know.

I've tiled kitchen and laundry, installed hardwood in LR, DR, and hallway. If I had squeaking in these areas I was able to silence with either deck screws or cabinet screws down through subfloor into joists.

Now prepping BR's for carpet. Have an area with loud squeaking in the dry winter months. Almost a popping sound rather than a squeak. I've screwed the subfloor down but it's made no change. Sound comes from area near center support beam under the house so I'm thinking it's joist and/or ridge beam related.

I've got a crawlspace so I can get to the area. What am I looking for and how do I go about fixing ?

[Kman]

If you are able to get under the floor easily enough, have someone walk on the floor where the squeak is coming from while you watch for movement from below. You should be able to spot it fairly easily.

What does the subfloor consists of? Is it more than one layer?

If you have two layers of plywood/OSB etc., then you could have movement in the upper layer which would be a little tougher to spot. You could also have a bad spot in the lower layer that is compressing, or unable to hold a screw.

[Tackle Anything]

squeaking subfloor

I'll get in the crawlspace and be looking while my wife walks above.

The subfloor is one layer of OSB. I've put so many screws in it that I'm hardpressed to believe the subfloor is loose on a joist. I'm leaning towards a joist being loose on the center support beam. Sound reasonable?

What I've got now are louder popping sounds instead of the quieter squeaking I've experienced in other areas. Screwing down the subfloor in those squeaking areas took away 99.9% of the noise. Screws in this new problem area have had no impact and I can feel no specific play in the subfloor when walking on it. There is probably a 6' x 6' area of subfloor I can walk on to make the popping sounds and the sounds always come from up near the main beam area.

If it turns out I'm on the right track and it is a joist(s) loose from the main support, is there a fix ?

[pushkins]

If it's the joist, then the solution is very simple, add a joist hanger to the end that is moving, make sure you use joist hanger nails. This should take away any movement that the joist is having on the bearer beam.

One thing you might want to look at is the way you screwed the sub floor down. When installing sub floor you never want to start nailing/screwing down from the outside working your way in, preferably you start on one end and work your way to the other or start in the center and work your way out. The reason behind this is if you work your way inward and the joist has a sag it is difficult to pull down the center part of the sub floor hard against the joist.

You might want to remove your screws get in the crawlspace and add a bead of sub floor adhesive to the joists in the area effected then re screw down your floor starting in the center of the effected area.

As you have already installed the screws with little to no solution I'm kinda on the same page as you though that the problem may well be the joist.

[uncle knackers]

Gidday, l have actually just made a video that tackles that exact question. It may just relate to your issue but it certainly is worth a look. Go to youtube and type in Uncle Knackers. Here you will find a possible answer to your sub-floor issue. Cheers.
Ps. Let me know how you went.