I am adding a bathroom to my home and installing a new tub. It is an American Standard with a composite frame and a ceramic (I assume) coating over the top. It is being placed in an alcove which I have framed to the manufacturer's specs. and squared it. The existing floor is not level, so I have shimmed the tub level in all directions. When the tub was slid in to place, it was a snug fit, but no excessive force was needed to get it in to position.

Before I nailed the tub to the studs, I noticed that there was a squeak coming from the tub rubbing on the studs whenever weight was placed on it. I figured this would go away once I secured the tub to the studs, which I did with roofing nails per the manufacturer's directions. The squeak did not go away.

I checked all of the support points - the ledger board at the rear of the tub and the front lip of the tub resting on the floor - and I have good contact at every point I should. I even added shims along the front lip of the tub (now at 6" spacing) to ensure there was good contact with the floor.

The tub is obviously moving slightly causing the squeaks. What can I do to correct this? Is it advisable to put downward pressure on the tub and then secure it, trapping it between It's low point and the nail? I have hesitated to do this in fear of flexing the tub and eventually causing cracks in the ceramic.

I have also thought of increasing the acove size slightly by planing back the studs a bit. If I left a tiny gap between the tub and stud, it would take care of the squeak, but what other problems would I run in to down the road?

Any suggestions, anyone?