The lateral movement allows a bit of play for your tile layout. You still want to set the flanged drain as accurately as possible...but the lateral play of the secondary ring, or the "adjusting ring", does allow for some lateral shift if needed.

You can have the adjusting ring centered in the drain flange by having an accurate initial installation of the drain flange itself.

The flange depression will be filled with thinset. With the drain grate threaded into the adjusting ring, you then set the adjusting ring into the thinset as you are setting your floor tile, thinset will squeeze up through the holes around the circumference of the adjusting ring.

The adjusting ring gives a bit of lateral play, as well as a bit of leveling/tilting play if needed.

Cataan you are asking so many questions and have yet to really get started. I fear you are reacting to the job instead of planning for the job. I think if your crew is allready plowing forward you should really have a solid plan in mind.

Cutting a hole in the subfloor for the drain for example might imply to a skilled builder that you have not blocked the subfloor around the drain. If you had you might have been asking this question earlier in the week.

What time frame have you allowed for curing? How long do you plan to flood test your new shower? How will the shower floor be protected after flood test? These are the basics.

One side of the drain has been blocked - should both be blocked?

Both sides blocked. 3/8 sanded ply being installed on top of 3/4. I'm just being paranoid since the crew has never installed hydroban.

The mortar bed will cure for 72 hours (possibly longer with the weekend). Have to discuss with contractor about flood test.

For a contractor who has only used waterproofing linings for traditional showers do you think the hydroban liquid would be easier than the sheet membrane? While I like the idea of the sheet I want the install to go as smoothly as possible and do not know what the learning curve is for it.

"For a contractor who has only used waterproofing linings for traditional
showers do you think the hydroban liquid would be easier than the sheet
membrane?"

Personally, I think HB liquid is indeed easier, faster, and gives a better shower than traditional CPVC/CPE membranes sandwiched between two layers of mud. I prefer sheet of liquid topical membranes over CPVC/CPE.

Liquid topical versus sheet topical? For me, sheet gives more peace of mind, as with a sheet membrane I'm not worried about mil thickness, pinholes, fabric reinforcement, etc, etc.

But you simply have to be conscientious in order to get a good installation.

On the flip side, with sheet membranes you need to be careful thinset coverage behind the sheet. With sheet overlap. With not too many built-up layers in the areas of overlap. With pinholes in folded corners, etc, etc.

And yet again, you simply have to be conscientious in order to get good installation.

I wouldn't want to railroad a resistant "but I've always done it this way" installer into doing something for the first time. If you have to strong-arm an installer with "You'll use this new product or I'll get someone else..." type of thing? It might be better to actually get someone else. But I'd have no qualms about letting someone use it for the first time if that someone is eager to try something "new", is willing to embrace the next generation of membranes, and who is willing to do a bit of reading and youtube watching to see what installation methods are recommended by the manufacturer, as well as what techniques have been developed by installers out in the field.

Of course, "new" is relative. These products have been around for quite a few years.

Hopefully you and the installer have already read Laticrete's pdf. You've already watched Laticrete's installation videos. I'd even encourage you to watch videos like this. You take a little from here. You take a little from there.

The big thing with liquid membranes is coverage. You want a good substrate for the membrane to go over. If there are gaps, cracks, stress points, etc, use fabric as needed. When the membrane is applied, work it into the texture of the backer board to prevent entrained air that can later show itself as pinholes. Get it on the wall. Back roll it for even coverage. Use a mil thickness gauge if needed. Then leave it alone and let it cure. After it cures, look for issues. Pinholes. Thins spots. Fix them. Let your repairs cure. Then install your second coat.

FWIW, my very first Kerdi installation was photographed by trade magazine for a "how to" article. Those are the same photos I used in the Kerdi tutorial thread that I wrote way back when. You have to start somewhere...

Good luck!

Do you have a preference for the trowel material for smoothing the sheet membrane? Metal vs. plastic vs. solid rubber?

The ply is technically 15/32 so more than 3/8 but not precisely 1/2 -- total subfloor is 1-1/8.

1-1/8" is fine. No worries. A shy 1-1/4 is better than fine. Double no worries."

Do you have a preference for the trowel material for smoothing the sheet membrane? Metal vs. plastic vs. solid rubber?"

For smoothing sheet membrane, I got in the habit years ago of using a 4" drywall knife to initially embed the membrane in the thinset. I draw it across the membrane at a fairly low angle to embed the membrane's fleece in the thinset. When I get to a seam where I'm pulling thinset out of a seam, I'll raise the angle as I get to the overlap so the pulled-out thinset stays on the knife instead of getting shmeared all over the membrane.

When the embedding is done, there have been a few times when I have gone over the entire surface with the flat edge of a trowel at a very flat angle. With the front edge raised maybe 1/4" off the membrane. If it wasn't flat already, it'll flatten everything out quite nicely.

You can certainly use the flat edge of a regular metal trowel. I've never used wood or rubber. The less friction the better.

Friday the 3701 goes down then cures for 72 hours. This weekend I am going to employ some commando testing. According to Schluter tech support, kerdi can be bonded to PVC with kerdi fix -- I want to see how well it bonds laticrete sheet tape.

Kerdi-Fix is a great sealant. I've used it to bond the membrane to window jambs, etc. Metal, PVC, natural stone, it'll stick to things you don't want it to stick to while providing a proper infiltration barrier.

It can be used with Hydroban sheet products as well like the HB Sealing Tape. In addition to thinset, you can use it to seal the HB sheet to the HB drain. No need to test. It'll work.

Silane-based adhesives have advantages over typical silicones and PUs, etc.

I don't think Laticrete loves Kerdi Fix. I don't like much of the Schluter Kerdi Line up but I do love Kerdi Fix, and use it on my jobs. I used some myself to seal Laticrete's Hydro Ban Sheet Membrane to my last Kohler Under mount tub and to the window in the last steam shower I built.

It's slow to cure. About an 1/16"-1/8" a day when roughly 1/32" thick. I have tested it and found it sets up under water but never rushed a flood test sooner than 18 hours if memory serves me right.

I'm waiting for Laticrete to come out with their own. I would like to know who makes Kerdi Fix for Schluter. Many people swear by Sika Flex or something like that - I have never tested it.

Remember that Laticrete's membrane is thicker than Kerdi so it the membrane might want to fight back or realease a little. The fleece if different too. More furry. I would be bracing the connection with a small amount of weight and the brace I would be using a bond breaker tape on it.

Thanks guys! I was not able to buy hydroban sheet corners (only sold in packs of 12) so I picked up kerdi corners instead. Kerdi normally involves multiple overlaps while hyrdroban sheet wants to avoid them. If I use a kerdi corner, since it is thinner, do you think I should overlap it with the hydroban tape? Or maybe coat the back of it with kerdi fix as a way to thicken it, let it dry, then set it in the mortar in the corner.

Mongo, when you say [It can be used with Hydroban sheet products as well like the HB Sealing
Tape. In addition to thinset, you can use it to seal the HB sheet to the
HB drain. No need to test. It'll work.] do you mean instead of using thinset (which I assume is what you mean) or in conjunction with the thinset?

http://www.stonetooling.com/Laticrete-Hydro-Ban-Seal-and-Adhesive-10-3oz-Tube-p/40.91730.htm?gclid=CNbe8q3t-MUCFVM1aQod5oAAWg&Click=3227

Man it is hard to find Laticrete products in stock other than via online ordering. Schluter seems to have taken hold of the retail and contractor market.

"...do you mean instead of using thinset (which I assume is what you mean) or in conjunction with the thinset?"

In conjunction with. Example, Laticrete normally wants you to thinset the sheet directly to the drain. That's fine, you can do it that way. For a better bond than thinset-to-plastic, we had a discussion in another thread about painting HB liquid on the drain flange, letting it cure, then thinsetting the HB sheet to the HB liquid.

For your question, I was inferring that you can trowel thinset on the drain flange. Then run a bead of sealant around the inside edge of the drain flange. Then bed the membrane in the thinset. The thinset will bond the membrane to the flange and "fill the gap" between the membrane and the flange. The sealant will bond the edge of the membrane to the flange, but with (my opinion) a more durable bond than you;d get with thinset.

My opinion.

So encompass the area like below (the black is thinset the red is kerdi fix):

Maybe more like this:

The red is a bead of sealant that's on the inner part of the recessed portion of the flange.
The yellow is a "ramp" of thinset that runs from the outer ring down to the recessed part.

Whatever you do, the goal is to have the membrane fully adhered or bedded, regardless of what it may be adhered to.

Probably one of those things that's easier to do than to describe. You just do it.