I would be concerned enough to ask him for more details as to why he gave you that guidance. Can he explain his thought process, or provide building codes for your areas that would demonstrate his reasoning. Repost with what he says; then if his advice turns out to not be right you probably need to work with someone else. that being said, curbless showers are still pretty new so if this is a contractor you like and trust and has other good experience, then you might still go with him. My contractor is my stepbrother and I knew he would do an excellent job, as he had done alot of work on my Mom's house and the quality was excellent. Plus, he would have heard about it every Xmas, Thanksgiving, etc if he messed up the job. But, curbless was new to him...still I had confidence that he could learn how to do them and do a good job...and he did.

Barb, If you're still considering the Lacava system, shoot me an email: Chris@WrightWorks.net I've used the system and there are definitely some challenges to waterproofing the perimeter of their pan. I'd be happy to pass along how we performed the install.

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.