[HayZee518]

i have a jucauzzi all fiberglass tub 59 1/2 X 42" X 28" - it's a one piece tub that sits on its own precast base and is screwed to the floor through its base flange. along the back wall is a 2X4 stringer that supports that part, the outer rim has a 2X4 stringer supported on two 2X4 legs screwed into the end walls. to hide everything I used 3/8" wainscoting with decorative mouldings top and bottom. I have no fiberglass insulation anywhere inside. if you are having stability problems I'm afraid you may have to start from square one and start the installation from the beginning. I don't think any after the fact repairs are going to fix it!