Shower Pan Tile Adhesive Question

[Kethan]

I poured a shower pan as directed. In the pan there is a liner. Above the liner is a second coat of mortar (as directed). Over the pan I attached tile, grouted, and sealed. After one year, the grout began to crack (thin set in the seam). I removed the grout and removed excess thin set. While doing so, I noticed that the entire shower pan (under the tile) seamed damp; the adhesive was loose and no longer affixed the tile properly.

My question is, what adhesive should I use to correct this problem...or is this a symptom of another problem (loose tile, improperly sealed, etc.)? Should I use a sealer on the concrete pan before applying the adhesive?

[HayZee518]

I made a shower pan that measures 40 inches by 72 inches. The floor rests on 2X10s on 12 inch centers. The subfloor - pan is close celled particle board. On this is 3/8" semi wet/dry mortar and sand mix - three parts sand one part portland cement. This forms the first base coat. It is spread out and troweled smooth then pounded with a block of wood and a 5# sledge till it was rock hard. Then let dry. Next comes the vinyl pan and drain. the drain glues over the 2" drain pipe and just below the floor. The vinyl uses silicone sealer to adhere it to the flange. Then there's a bolt on flange that sandwiches the vinyl to the drain. Next the corners are formed internally in the corners of the pan and I used xontact cement to hold them together in the corners. Next comes the other layer of portland - sand mix. Again I pounded this into place with a pitch towards the drain. This was left to dry overnight. I mixed up the thin-set mortar and buttered each tile and applied it to the set up concrete. I just didn't spread out a bunch of thinset and pushed the tiles into it. When the tile quickset was dry, I mixed up the grout and squeegied it between the tiles in every direction. Clean up was with a burlap bag several times. No sealer was necessary for the joints. All shower pans no matter how dry they look ALWAYS are wet!
About repairing your floor you may have to chip up the tiles and use quickset mortar buttering each tile. try to clean up between the tiles of all quickset and other grout and then apply the grout.

[Kethan]

Thank you for the additional information. I am working on this shower again this weekend. I will apply some of your ideas.