I installed a Lasco Fiberglass Shower Pan per the manufacturers directions about three years ago. I used four mounds of mortar for supporting the bottom as described in the instructions, surrounding but not contacting the drain area.

This morning I was using our unfinished downstairs bathroom which is directly beneath the bathroom this shower is in. I noticed a small puddle of water on the floor, and traced it to the area underneath this shower. I could see where water was coming through the car decking (the subfloor for the upstairs bathroom). When inspecting the shower pan I found a crack in top layer of the base, about five inches from the drain. When I press on the pan the crack opens just slightly, so it appears this is where the problem is stemming from. I'm guessing this crack is about 3-4 inches from the nearest supporting mound under the pan.

Obviously the permanent fix would be to tear out the whole thing and start fresh, but is there a temporary fix to repair the crack so I don't end up with a rotten floor under the pan? This crack wasn't there a couple days ago, so I know it hasn't been leaking for very long.

By the way, my neighbor (he makes garden art) makes fiberglass molds for creating his statues. Would it be possible to overlay a few pieces of fiberglass over the cracked area as a temp fix? Any other suggestions?

 

You could buy an automotive fiberglass repair kit and do a temporary fix. I only say temporary due to color match. It won't look great but will cure the problem. Or ask the neighbor if you can get enough material to do the patch and maybe a little assistance. Good luck.