I suppose you could Redguard it and tile away. Nothing ventured, nothing gained. Personally, I would rebuild it....but you say that's not an option. We really don't know if there is a vinyl/rubber liner under the mudbed...nor do you, apparently....and a redguard membrane, if that is the case, is superfluous. At this point, just paint the stuff on and tile away. It may last awhile...it may last forever. You pays your money and you takes your chances....

I think most of the unhappy stories about tiled floors are due to the use of Marble and not the fact that they used tiles. If you have a a good GC and tile person, there should be no problems with a tile floor. My current 14 year old showers have tiled floors and have had no problems. All my new showers will have tiled floors.

I agree, they messed up. However, to fix this would require ripping out the entire thing and this small remodel project has already spanned over three months. We’re ready to be done with the whole experience, not drag it out for another three months. We’ve already negotiated discounts to the final project cost based on issues with the shower, so while I’m not 100% happy with the shower, it is something that we can live with. It’s functional and we realize that our space was challenging to work with. The pan is solid everywhere except this one corner and the water drains properly. The entire shower enclosure was a sloppy install from a cosmetic standpoint, there is no way that I would want the same plumber to redo it. We are very happy with how the rest of the bathroom turned out, the shower is the only problematic area. It’s annoying but not worth the hassle of forcing the contractor to rip it all out and start over, especially if we can level the threshold enough to install the shower door. All of the weight is supported by the walls and crossbar, I just need a level surface to rest the skinny little threshold piece on top of to guide the doors and have them open/close properly.

Abel, in the pro world its a tearout. Since its your home id still suggest you tear it out now and do it properly and eat the small costs. Hardiebacker on the curb involves fastening said hardie THRU the liner into the wood. Painting aquaD over that is not an accepted industry approved installation nor does it meet standards and it will be one of the first areas your shower fails.. Even If you had done a proper flood test it is voided the second you proceed to put screws anywhere in the liner that are lower than 3" above the finished tiled curb. lastly you do not want an additional coat of waterproofing on top of the mudbed either. It is not that hard but there are very specific steps and measures to doing it correctly. If you start over share pictures once torn out, and I will walk you thru doing it correctly step by step.- best