Why is this occurring?

There are a myriad of reasons that your shower floor is failing, below are just a few. 

1.  The mortar bed was never sloped properly leading to weaker points that have created cracks in the grout and has allowed water to penetrate underneath the tile causing efflorescence. 
2.  Improper maintenance of your shower.  If silicone has not been replaced when damaged, water has been able to penetrate underneath the tile. 
3.  Cracked/loose tiles that have allowed for water penetration underneath the tile floor. 4.  Missing, damaged or incorrectly installed shower membrane.

Our Solution

It is not always feasible to do a complete shower remodel.  Our solution is a less intrusive option compared to a complete shower remodel that allows for zero grout lines, complete water proofing and durability.  The solution is a marble chipped epoxy floor.  Similar to what you have probably seen in locker rooms, hospitals, restaurants and other commercial areas. and now being introduced in residential settings.  These floors are made to last and to stand up to the harshest of uses.  The material comes in a vast array of colors allowing you to match similarly to your wall tiles.  No more dirty and discolored grout lines or cracking grout, the end result is a beautiful terrazzo marble look in a seamless shower floor.