First and foremost, I'm not a lawyer and there may be some on this forum with better or more correct advice. What follows is simply my opinion. In general, the better way to start remediation would have been to give the GC a chance to correct the deficiency. Not that you have to actually let him. But just start a discussion. You stop work. You show him the analysis you got from QD. You have a discussion. On your end, your argument is along the lines that the person the GC hired to do the work did not do it IAW industry/manufacturer/product guidelines. The letter from tech support confirms that. Your argument is that the GC himself failed to supervise the work and ensure that it was done IAW with the above. Your want the job done, done right, and done yesterday. You desire is to bring in another crew that is familiar with the product and who can do the installation correctly. THEN you quibble over nickles and dimes. Money spent versus money to be spent. Now, your GC may simply fold and give you what you want. It depends on the size of the job he is working, and the relationship he has with the tile sub. His tile sub may do the same, depending on his relationship with the GC. Or they may fight back. The tiler's argument could be that he didn't get a chance to fix his work. The GC can have the same argument. And of course your argument is that they should have done it right the first time. Right now, "as is", I'd say if you didn't even have a discussion with the GC about making it right and the possibility of bringing a new crew in, then all additional costs are on you. I know that sounds harsh, but that's generally the way small courts see these cases if it was to go to court. Are you familiar with a Mechanic's Lien? If one of the people who did work on your house doesn't get paid, even through no fault of your own, that worker can sometimes place a lien on your property. I don't want to get overly dramatic with the idea of a lien, but it's something to be aware of. In an ideal world, the tiler would take no money for his labor. The GC would take no money for his labor and oversight of that portion of the work. The GC already offered to pay for new tile, that's to your favor. The idea of you absorbing the difference for the higher labor seems fair. Once things are worked out, I recommend you get things in writing if you think there could be repercussions down the road. ie, you and the GC work things out, you think things are settled. But if the tiler still thinks he should get paid for his work and the GC refuses to pay him, the tiler could get ticked off and file a lien on your home. It'd be a good idea to get a Mechanics Lien Waiver and have any and all subs who do work on your house, to include your GC, sign it before funds are disbursed. Again, the above words are just my opinion. Good luck and do report back.

We are in the process of interviewing several potential contractors. After these screening interviews, we will ask for bids from the 2 or 3 contractors who are most knowledgeable and compatible with us and our project. We know what we want for most parts of this bathroom, but we are still trying to understand the best way to design an accessible shower. We want to add it now as we rework our main floor so that we can eventually "age in place". The four contractors we have spoken to so far have looked at the joists, sub-floor and open access from below; and all confirm that we can readily recess the floor under the shower. They differ, however, in how they would handle the shower pan and drain for this curbless accessible shower. A couple of them have suggested the Wedi system with a linear drain. Another talked about the Schluter system, and a fourth contractor said his tile man only does a traditional mud base with a central drain. They all said that floor in the main part of the bathroom could be level and the sloping would all occur within the 4' x 4' shower (1/4" per foot). Most would put waterproofing under the whole floor, but one typically extends the waterproofing just a foot or two beyond the shower entrance. Are there reasons to go with the traditional mud base vs the Wedi (or other foam type backer)?

I have built two curbless showers with in the past year and a half. Both where built using Ditra, Kerdi and Red Guard. I have been having more and more clients ask for trench style drains and have spend about 8 months researching these beauties. Quick Drain USA has a nice channel (trench) drain with excellent tech help and a wonderful website. ACO now imports to North America from the UK and I have found that their drain can fit on top of a Schulter drain rough in (this can not be done without modifying the stock unit and I'm sure it will void any warranty). All that said I should have much more answers to this specific question in roughly 3 months time. The more I look at the trench drains and the more we explore the options it creates it's no wonder the channel drain is the hottest look of any new shower. As far a a nice clean looking curbless shower with a simple Kerdi Drain the entire bathroom needs to be waterproofed. Toilets should not be placed too close to the shower entry because a typical floor mount toilet is the biggest weak link in a wetroom floor. A better option is installing a wall mount toilet or small covered curb (i.e. pony wall, glass block wall, frameless glass on low curb) that separates the toilet location from the wet zone. Make sure you pipe your new curbless with at least a 2" drain line (with properly sized vent line) your design and polumbing package might need a 3" drain line so even though you want the new channel drain you may need to install a standard drain in addition to the floor drain. It's hard to teach an old dog new tricks - Push your builder or tile guy to research harder. Be prepared for extra costs. Framing changes, concrete work and structural engineers may need to be used. I designed my last two around standard framing and raised the transition from the hallway to the bathroom to 3/4" - 1" (Solid hardwood reducer at doorway) and pitched everything back to a single Kerdi drain.

First..do a moisture test on your existing slab. You want to see if moisture vapor is coming up into the basement from under the slab. Tape a 2' square sheet of poly on the floor and see if there is any moisture under it after 48 hours. If the moisture is significant, it might play into what type of membrane you use on the floor. Memebranes like Hydroban and Kerdi have similar properties when it comes to liquid moisture, yet differing properties when it comes to moisture vapor transmission. Significant moisture drive could actually lift and delaminate a topical membrane from the slab. If you have under-slab drainage or radon ventilation pipes, and foundation perimeter footing drains, you should be in fine shape. I'd make it a wet room, pretty much follow Bill's advice; -slope the entire floor to the drain. -topical membrane on the entire floor and up about 6" on all the walls, or just fully membrane all the walls. Fully membrane the shower walls. -ventilation. Don't skimp. This room will be cool and the basement itself is typically humid, so latent drying action will be less than in an upstairs bathroom. Do what you can to eliminate moisture vapor as it is generated. -I'd not insulate or heat the floor. You might have to balance relative humidity in the basement as a whole with a heat source in the bathroom. If you do have vapor drive into your basement, it might help to have something as simple as an IR bulb on a timer to help with the initial drying of the room. For a humid, slow-to-dry shower environment; A non-porous porcelain tile might be better than a porous natural stone tile. An epoxy type of grout might be better than a portland-based grout.