How did you flood test it and how did that drain? theres a lot of bad shower threads here almost always Pros bring up the flood testing process (after the fact). I would not bury the cement board i agree with you theres a lot of opinions out there on why..

Bottom of the cement board HAS to be buried. No fasteners for about the last 10-12 inches, and something has to hold it in place. You just don't let it go all the way down to the membrane.

Thanks guys.

I didn't flood test the liner but I did pour water in to test that the slope was ok and there were no dips. The water drained fairly slowly around the drain but as I understand it, the weep holes aren't meant to drain large amounts of water at a time (as in a flood test).

The cement board in question wasn't 100% straight so I had to add to the framing behind it which made it much better. I still have to pack the floor in, install a shower valve, and waterproof everything once time permits it, then it's off to tiling.

Should I regard the cement boards before doing the floor or should I waterproof everything after the floor and curb is done?

**On page 6 of the Durock installation manual, it shows a diagram of the cement board above the floor bed with sealant in between. This just adds more confusion as to what it is/isn't supposed to be =\

http://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/durock-cement-board-system-guide-en-SA932.pdf

I've neither heard of, nor seen that detail, or anyone who used it. I've seen sealant (silicone or siliconized latex caulking) used between a one piece shower base and cement board. But never where a mud bed is used.

And to my earlier point about not burying board , the bead helps w/ wicking.

Its an outdated flawed method the type shower your building and the MFG knows it. You further cheat yourself without a full water test to check your contact cement corners and drain connection

It wouldn't take that much to change out the drain to one that would accept a topical waterproofing system.

The worst would be the money that was spent on the membrane you have now being thrown away. But in this case, it would be money well lost.

yep lose the $150 and move on I agree w /bill . The cool thing about a skilled DIY job is that labor is free. Buy the best materials and build yourself the best shower if you have the chops.

That's the way to go. Purchase a system with a drain adapter (USG, Kerdi, etc.) The liners are fading into history as they should. Topical systems are the new normal and far superior.

I see the gray area on shower base detail has been exposed. There are no details that allow the cement board into the mud base. Yes I understand Bill's point. How to fasten the lower portion of the board. After a recent discussion on this topic it was brought to my attention and I agree the only practical method would be Alternate Receptor Base detail on page 250 of the 2016 Handbook. Stop the board above the liner with mesh & mud below. That fixes the fastening problem but not the wicking! The liner system can't disappear quick enough. We can still mud the base but waterproof on the top. (not both).

Can someone post a link to the drain system that's being talked about? I don't think I'm familiar with them. The only thing that might be a pain is to remove the current drain I have since I have a concrete foundation. I might have to chip away around the drain to remove the old and install the new.

You do not need to remove the existing drain. The USG system has a adapter #170208. This will replace your existing drain ring and allow the USG integrated drain to thread into it. There is only one drain to order with their system. It will have a cover in the box to allow you to screed deckmud keeping the drain flange clean. You will order the grate separately. http://www.durockshowersystem.com/en.html