WE CAN HELP WITH SPONGY TUB BOTTOMS AND CRACKING! 

One reason you might be experiecing cracking is due to poor initial installation procedures. When your fiberglass/acrylic unit was installed, mortar, which is a cement mixture, should have been poured and then the fiberglass/acrylic unit squished down into the cement mixture and allowed to set. This process can also be performed with sand. When this is not done there is an air space of about 4" between the tub bottom and the sub floor. The tub will not have sufficient support to properly hold weight if this process was not performed initially and will begin to crack over a period of time.

You may first notice the problem as a bounce or give in the floor.  Later cracks can be seen then they start to leak.  This problem is caused by the lack of or failed support of the floor of your unit.  We can correct this damage without removing the tub or shower.  We first add support to the tub floor by injecting foam beneath the tub.  To repair the cracked floor we overlay it with 3 to 4 layers of fiberglass and reglaze with a new finish.

BATHTUB BOTTOMS REBUILT & READY FOR USE IN 24 HOURS. 

The gel-coat paint finish on fiberglass tubs and shower are about the thickness of an eggshell (acrylic surfaces are slightly thicker).  As you can imagine it doesn't take much to damage the finish on these units. The good news is that they can be repaired and made to look like new.  Some scratches on fiberglass finishes can be sanded and polished out.  Don't try this yourself, the wrong sandpaper or polish can damage some finishes.  It is best to leave critical work to the professional.