I am in the process of installing bamboo click lock 5" by 60" planks. I had to completely remove the old gypcrete over tonge and grrove plywood over joists (second floor condo) and float new cementious leveling compound because the floor wasn't flat mainly due to a single joist/header installed that cause a ridge about a third way into the 21' side of my 21' by 14' rectangle living room.

I knew I had a noisy joist before and extra screws didn't help it and now I have my flattened cememtious base over the old tongue and groove plywood.

My contractor says the next step is to access through the Sheetrock ceiling from underneath the floor into the joists for a look and possible blocking/shimming with wood glue like liquid nails or something (luckily I have a neighbors garage beneath)

Question: What would be the best option for underlayment that might possibly quiet the noisy joist a little maybe to the point where I choose not to continue with access from beneath to fix.

I was going to use Heathier Choice Sound solutions with vapor block but that was before I found my joist will still be noisy without further work from below.

Suggestions?

Thanks all

How do you know its the joist making the noise?

who and that determined that?

if its the joist what is going to be "shinned" and blocked with glue?

the only way I see a joist making a noise is at the fastening points to a plate/etc no joist hanger used or the like.

I don't know (and he doesn't) for certain what is making the noise. And i don't know details of what could be a fix. But many screws installed from the top into the joist didn't resolve it.

But short of tearing up the flattening material and going in from the top (which my contractor said would not be wise), he feels the best way to approach it is gain access from the garage ceiling beneath the area making noise to troubleshoot and hopefully stabilize/repair.

is it plywood or OSB?

if the problem was there, why were the levelers poured without correction first? seems a little late in the game no matter what way you go..

most squeaks are caused by fasteners..there may be missed nails riding the joists causing it..hard to say but no matter how you do it now will be expensive
..

Plywood joists. Not solid beams. Plywood vertical and plywood horizontal make up the "I" beam joist. I will try to post a link to a pic soon.

And it is 5/8" tongue and groove plywood over those. . Nailed (not screwed) down to the joists. Structure is approx. 27 yrs. old.

Do you believe a fix is possible from below?


Thanks JamesTRD

i want to say yes and will..

as long as there is ful access..top or bottom shouldn't matter.

i believe it is the subfloor..it always is...shims should correct it..

in the prblem area drive shims in every 8- 12 " depenedent oneach side of the joist around the porblem area..

draw a bead of construction adhesive at the seams of joist/subfloow.
work it in wiht your finger..this on bothe sides of the joist..

this should makes things nice and quiet

what a mess of typos..this site needs an edit button..sheesh

I've been meaning to mention this to you James...

Simple Solution - Use Firefox that has a built in typo fixer upper, or craft your responses in an editing program and paste them into the response box.

Or just take more time.