As with shower tubs, acrylic shower bases are too often improperly waterproof or not protected at all against water damages. Unfortunately, contractors still widely use cement and paper color sheet-rock instead of waterproofing membranes. We waterproof these type of showers using the Schluter-Kerdi membrane which we seal to the acrylic and deploy it all the way up to the ceiling. The membrane prevents moisture and water from reaching the shower structures and eliminates mold and mildew issues. Bellow, are examples of acrylic shower bases tile installation projects:
Acrylic base – color punch 
Acrylic base – tumbled marble
Acrylic base – blue glass 
Acrylic base – grey porcelain