From what I can tell my tile guy broke just about every rule in the book when building my shower pan and curb:

1. No pre-slope for liner. (Actually, 6 of 7 tilers I interviewed for the job said they didn't usually build a pre-slope but I built one myself before I let them lay the liner).

2. Packed mortar down around the drain without putting down some kind of material to keep the weep holes open.

3. Built the curb out of cement board rather than mortar thus piercing the liner with screws to attach the CBU on top of the curb and inside the shower.

I am just sick about this as it took me months to do the construction on this remodel and unfortunately a lot more money then I thought it would--but I tried to do everything "by the book" and waited another 2 1/2 months until he showed up.

Any ideas as to how to fix this or at least try to minimize what would seem to be some pretty big risks?

My plumber suggested coating the curb with a topical membrane like Redguard and to try to open the weep holes from within the drain with a hanger? Assuming this would work--how do I find the weepholes? I opened the drain and I can see where the liner comes in but can't seem to find the weepholes. Suggestions?

I suggested to the tiler that we break up the mortar around the drain, put something down to keep the weepholes clear, and repack with new mortar. He is unwilling to do this saying it will compromise the mortar bed where new and old mortar meet. He keeps saying I'm worrying about nothing and that no water will get down there having to go through tile, epoxy grout, thinset, mortar, etc. From what I read it seems inevitable and that is the purpose of the liner and weep holes in the first place!

Any advice anybody can give me will be greatly appreciated. I'm thinking of just breaking up the entire pan, taking off the CBU, patching the liner, and starting from scratch---it has already been seven months into this project--2 1/2 waiting for the tiler, but I want it right and don't want to take short cuts now. Or am I worried about nothing?

If he ran the membrane over the lower part of the drain body and into the wide part of the opening before installing the clamping ring, then you really don't have much to worry about.

The weep holes are primarily for moisture that might make it's way into the mortar bed, which is less of a concern these days, as most thin-set/mortar bed materials are made of elastomeric materials, which inhibits the migration of moisture to the mortar bed.

The nail holes in the curb are cause for concern, though, if he didn't slope the curb to the interior of the shower.