"So he built the sloped mudpan, coated it with Hydroban and installed the bonded flange drain with specified 1 1/4" height from the substrate and then when he went to install the tile he said that in order to get the tile height to what Laticrete specifies it should be (1/16" higher than the top of the drain) he had to build up the mortar and basically try and follow the slope with 1-2" of mortar. " If that's how he installed it, he completely misunderstood the installation instructions of the drain. The drain flange gets installed so the rim of the flange is 1-1/4" above your FLAT PLYWOOD SUBFLOOR. Not 1-1/4" above the sloped mud bed. If that's what he did, it's completely wrong. Again, the drain flange should have been installed so the rim of the flange is 1-1/4" above the subfloor. That 1-1/4" gap between the flange and the subfloor then gets filled with deck mud, and the deck mud then slopes upwards as it runs from the drain to the walls so that it's 1-1/4" thick at the drain and, let's say, 1-3/4" thick at the walls. An increase of thickness of 1/4" per foot over the 2' distance to the wall. When the sloped mud bed is complete, the drain flange should be set perfectly flush in the deck mud. Then the mud and the walls get hit with two coats of HB. You then tile the floor but leave a few tiles out around the drain. The actual drain cover (the metal grid) is attached to a threaded plastic piece that gets threaded (or screwed) into the drain flange. You thread it down so the top of the drain will be at the approximate height of the top of the tile on the floor. In your case, for standard tile, about 1/4" above the flange. So the drain height is set in relation to the tiles already set on the floor. Then you complete the floor tile by filling in the remaining tiles around the drain. If the deck mud was properly sloped, all you'd need is the standard 1/8" thickness of thinset to bond the standard 3/16" to 1/4" thick tile to the sloped and Hydrobaned shower floor. The beauty of a topical membrane like Hydroban is that with the Hydroban membrane being right below the tile, there can be no deep wetting of the shower floor like with a traditional deck mud bed where the membrane is beneath a 1" to 2" thick layer of deck mud. Your guy put 1-2" of mortar or mud on top of your hydroban membrane. You have a porous tile (marble) on top of that mortar bed. That 1-2" setting bed will likely saturate over time. If the bed does saturate, the moisture can bring minerals from the setting bed with it through the marble and grout as the moisture evaporates, you can end up with efflorescence on your marble and/or grout. And with the bed holding moisture, it can end up being a mold/mildew mess. Those are not certainties, but they are possibilities. Also, if he used thinset to make up that 1-2" thick bed, that could also be the reason the floor has birdbaths. Thinset is designed for "THIN" tile setting applications. Roughly 1/2" thickness max of thinset. The reason is because as thinset cures, it can shrink. That shrinking could pull the tiles this way and that, causing birdbaths here and there. I don't mean to be an alarmist. But if I'm reading your post correctly, your installer screwed the pooch on your shower. If you haven't seen it before, watch this Laticrete video. There's a bit of an intro, but do pay attention to the installation of the drain flange at about 2:30 into the video, and the installation of the threaded drain at about 4:30 into the video. The Laticrete system is an excellent shower system. Sorry for you troubles.

I'm just a homeowner, not a pro. But my tile pro is here right now building one new shower and re-tiling floors and shower/tub combos in 2 others. He doesn't use the cement boards. If you look up the Laticrete Hydroban Board instructions he does that, 100%. You can look at their videos and read the manufacturer's instructions online. There are area reps that you can contact if you have questions. You can also buy a download of the TCNA handbook for about $40 and read the shower sections of that. Very helpful to prepare you to know what questions to ask and what to look out for. There are other companies such as Schluter, Wedi, etc. Laticrete is just what my pro chooses to use. Contractors have their own preferred products and methods based on their experience, availablility, etc. It's good if they go to training sessions, seminars. conferences, etc as my pro does. That's always a good sign.

@Nona Muss - I understand exactly what you’re going through. My first contractor didn’t do a pre slope under the pvc liner on shower floor. We got that addressed - and then he decided to not use any of the three bags of white thinset (he purchased) to install the carrara tile on the shower walls - but instead used mastic ”because it was faster.” When we pushed the issue, he packed up and left. The second contractor (with over 200 4.9 star Google reviews) sent over his “business partner” to bid the work. His “business partner“ then said that he felt so bad for me re: every thing that had happened with the first contractor (including needing to rip out the slate bathroom floor bc several pieces failed to bond), that he would start the work himself ASAP + work over the upcoming weekend. Well, it turns out that he wasn’t a “business partner” - but a new employee. He produced fraudulent receipts for materials (that I reimbursed upon recipt per contract) - and stopped showing up. I did a quick background check and discovered that he had been in prison for over nine years for aggravated battery + fraud charges (had been out for 18 months). I asked the owner about whether he had done a background check - he told me that he hadn’t run it yet. After I told him about the results of the background check I did, the owner asked me if I noticed the scar on the guy’s upper arm - and then told me that when he asked the employee about it, he said it was from “being shot by a cop.” I swear I am not making this up. He also stole some jewelry from me. Third contractor - great guy - had just started work - and then was sentenced to 90 days in jail related to a third DUI conviction. My fourth (and final) contractor is AMAZING. The third and fourth ones are both TCNA certified - I didn’t hire the first or second one - my SO did. Although I don’t blame him for what happened. My SO had glowing references from two of his law partners who had used the first guy for several projects + did research on the second one (who was the second highest bid out of five). I thought that by now I would have not only finished two bathroom renovations - but also my laundry room + kitchen reno (which is close to starting FINALLY). I actually wish I had never even begun - my bathrooms were fine - just a little dated.

@joseph_corlett Thanks for sharing. I did not realize tiling over the existing was an option. Not sure we will go this route or not, but good to know in case we do. I am quite aware that improper waterproofing is no joke. This was a battle with my husband and flooring contractor (our good friend with over 40 years in the industry). I shared all of the horror stories I've seen on here with them both. This method is how he has done it for many years and the methods he used in his own home and many high-end hotel bathrooms. I know he wouldn't do something in our home if he thought it would fail. The actual installer couldn't explain the slope issue and was completely embarrassed...especially since I asked him about it needing to be 1/4" per foot. In the end I agreed with my husband that if he does the work "his" way and it fails, it is on him. If we try to tell him the "correct" way and it fails, it will be because he did it our way and would be on us. I will just probably continue squeegeeing the floor for now. There is an access panel in our closet on the wall where the valve is so I plan on peeking in there on a regular basis to sniff out any water.