cement board as shower pan

Alex,
I need to stay fuzzy on this until after the Total Solutions conference on Sept. 17-18. I'm sorry. I have a non-disclosure agreement with a couple of entities and I will be able to give the details after that. I am a professional of 39 years in the trade a can appreciate your frustration when someone says he has a better mousetrap and then won't show it. No we don't cut the board into pie shapes, PermaBase and Durock are the two boards that will work. A vinyl liner gets clamped into the clamping ring of a standard two part drain ( oatey , Sioux Chief). Liquid water proofing like Mapei Aqua defense or LATICRETE 9235, hydro ban are used at different intervals to actually "waterproof" the cement board, fiber mesh is used to "tape" all corners and wall to floor, verticle wall corners and threshold. AND a SECRET as to how the board is pitched with FULL support under. Again I'm sorry for the need to be so vague at this time. I will try the JohnBridge site and continue to post on this site after I am legally able to. Please be patient.

I'm impressed with the job that Christopher posted. That is GREAT work! We agree that 9235 is difficult to work with. I use Aqua Defense and Hydro ban more. I still use a fabric with it to "tape" ALL the corners. For a test, I did my process and then flood tested
a shower pan and left the water in it , unprotected with tile/grout, for SIX WEEKS. Not a drop. If my process can keep a pan waterproof for 6 weeks , it can hold up to a 15 min. shower. To answer the $200 question. NO that's not M-n-L. Materials only
using $90 cost for liquid waterproofing. In my market I get an additional $400 labor for about 2 hours work. Maybe some guys can't work that cheap but I'm ok with it. The tile install is above and beyond this cost. I am promoting the construction of a shower pan,
tile ready, using cement board and my technique. AGAIN I AM VERY GRATEFUL FOR ANY NEGATIVE COMMENTS. Unless I get the other side, I may of overlooked it and you guys are my piers and experts on this subject. I will be able to "Unleash this Revelation"
by the middle of Sept. But I am encouraged that there has been this much interest and debate on it. It shows me that maybe mud set bases may be going out and the newer products that are different may be the new standard .

Welcome back gentlemen, Hydro ban literature says fabric is required only "at all joint, coves and corners" I'm reading that from the literature I have in front of me.So, I'm not suggesting anyone should use a product for something it was not intended for.A mini unit has about 50 sq.ft coverage. Enough to do a standard (48x34) pan with multiple coats. The pros like yourselves buy in quantity. The $200 number I've used would be an average cost if you purchase only enough for one pan.The costs go down per pan since your buying in a larger quantity you will have enough material to do multiple pans after the initial investment. A commercial unit ( 5 gal.- 250 sq.ft. is not 5 times the price) I have talked with LATICRETE about the possibility of including fabric with the mini units and rightfully so, they will wait to see the response and acceptance of my technique first.

The quote "and it's acceptable by the TCNA" comes from Mike's question. I didn't say it was endorsed yet at this point. I said early in the thread that I have been contacted by the TCNA as to the process to have it considered for the handbook. That takes at least 2 years. They are accepting requests now for the 2011 book.

Let me ask a question first. Is it true that the traditional method of mortar base pre-slope EXPECTS that the water WILL penetrate the tile and grout AND the mortar.So, water transferring and being trapped into the mortar
is just part of what is to be expected. Weep holes are designed to allow the water an escape but I'm sure you know that they can't be 100% effective in doing so. I'm trying to waterproof the pan above the substrate ( mortar in the traditional case) My liquid waterproofing is in theory doing the same thing as the liner except that the water isn't trapped below.Any water that penetrates the tile and grout(this will be a very, very small amount) will evaporate up and out. Not down and out only.

Am I thinking so wrong here? EVERY mortar base I have taken out had standing water trapped in the liner.No one has been able to actually prove to me that weep hole/pre-slope combination will work all the time. You will say that the pan was improperly built. Then EVERY pan I have seen HAS been improperly built and I go back to my statement that some of the problem is that we are not training the younger guys the proper technique. So, this technique I have come up with replaces mud set pans,does it well,and does it for less that the higher priced alternatives on the market. I wait for comments and again welcome critique.