Hey There,

A few things can cause a floor/deck to squeak. It's never the actual flooring material that squeaks though it would be the framing structure it attaches to.

1. if the deck joists were mounted into hangers, the hangers must be glued first otherwise every step you take the joist rubs against the hanger and squeaks

2. if non coated nails or screws were used (seeing as its on the exterior) the weather will breakdown the metal and cause them to loosen which results in squeaks every time they get stepped on.

3. this looks like trex decking material with the undermount system, based on the pictures im seeing. If they boards are not properly sucked down into the fasteners they will rub causing a squeak.

The unfortunate thing is that any way you go about it its a big job to eliminate the squeaks at this point.

Hopefully this helps, good luck

All I can say is I did not know you could have black deck flooring. It is beautiful, but does not compare with the view off the deck, and if nothing else, I am positive that mountain doesn't mind a little squeek between friends?! congrats ; )

no, my dear, and I am sorry you are not happy with whatever is the problem. I just know that many, especially me, would jump at the chance to be where you are, if our big problem is a squeek. it is absolutely gorgeous. I know I am not saying this properly, I understand how it feels to have something not work right. i just can see myself standing on that deck while i am calling them on the phone. Yuuu-um! That is it, I want you to stand out there and enjoy it, while you are telling them off. serenity and getting it done right, now that is heaven. lol ;)

Not to sure who azek is?

but what is the material wrapped around your joists?, if its rubber theres your problem right there

It's not rubber, but waterproof sheating.

Depending on how it was installed if the waterproofing if its up underneath the decking then the issue would be that the water proofing material would be rubbing against the mounting system causing the squeaks.

That is just a best educated guess though based on the pics.

Hope it helps