I have found after years of building showers that you can not pick one product and say this is the be all and end all. Schluter targets the masses and offers up "Simple, Easy, and Quick" methods. This is what you want to here. You do not want to hear that hanging sheet membrane is tricky. You do not want to hear that a shower needs to be flood tested. You do not want to hear that cement board is heavy and the screws are $20.00.
What I want people to understand is that this procedure of building a shower is not as easy as building a closet organizer and that there is a lot more to consider. I see junked bathrooms every week hitting the dump site. Brand new floors, brand new tile - maybe 2-3 years old at most. It is a silly waste of products.
This debate with Jim has shed a lot of light on the use of drywall in showers. Why Jim pushes a procedure like this makes no sense to me and only furthers my belief that he in fact works for either Schluter Systems or John Bridge Tile Forum. I would rather Jim comment on his favourite membrane and it's install with cement board and non-modifed thin set.
This exact debate send me back to my building department and made me re-check with both the TTMAC, ANSI, NTCA as well as speak directly to Schluter's top tech.
Drywall is only listed as an acceptable backer - this does not mean you should use it in a shower build. Never in a curb and the reasons are many. If you spent your life working around job sites and playing with wood you would realize that wood swells, it moves and it checks. Most builders do not add any extra blocking on the top and bottom plates. This step is labour intensive and not required by code. That and the plumber, HVAC guy, electrical, vaccum installer, low voltage dude and the like will all bitch about the extra blocking. That said this blocking does wonders for keeping the studs straight. Preventing twisitng and warping.
We all have seen popped drywall screws before. Results caused by warping, twisiting, drying and such. Drywall offers up little protection from this effect. Solid blocking can keep those wall studs straight. Cement board vs drywall is night and day. A stud will not twist free from a cement board screw but can from a drywall screw. Think about it.
I use a lot of Green EBoard in my showers. I cleared this board with my local building inspector and love working with it. That said it is bio degradable - this worries me some since how can a board that bio degrades work in a shower. For this reason we waterproof the floor and walls. Water does not see the board at all. Much like a kerdi shower with drywall. The difference is that the Green EBoard is way stronger than drywall and their is no paper face to delaminate during tiling.
Often a tile chips or a client prefers the grain of one tile switched. With cement board, Wonder board, Super panel and Green EBoard I have no fear busting out the hammer and screw driver and banging that tile out and replacing it. With drywall or a foam based board the process is much less likely to be executed without damage to the drywall or foam board. Yes the use of foam boards and drywall is easier - but not better.
Our skilled trades are aging, The average age of a skilled trade in North America right now I believe 58. These products designed for men with bad knees, bad backs or for the commercial crew wanting to bang out 7-10 installs a day. What we get in our local neighborhood depends on so many factors. Many of us forced to shop at box stores and this is quite scary.
The best thing anyone can do is their homework. Look this stuff up. Call your building department. If you are hiring a crew specify that industry standars be followed. Simple lines in your emails like "All work to conform with the latest edition of ANSI or TTMAC guidelines" will protect you from those not properly trained or not following industry standards.
If you want to "Flip" a home and don't care if it is do right or how long it will last then "Shame on you". I can not tell you how many times a meeting has resulted in tears from a young family when I tell them the entire shower has to come out. A young family who can barley afford their new home and now is faced with a total redo of the shower. It's sad and wrong.
As a new homeowner you should check that a newly renovated home had permits. Check if a flood test was done. Check if a damp proofing inspection was done. If it was newly renovated to flip add a clause in your home sale to say if the shower was not built to local building codes the owner is responsible for upgrades. Then do an inspection from the back side. Look for proper install methods.
I often get accused of "Hating" Schluter - I don't. The simple fact that I point out these false claims does not sit well with many tile men and builders. Schluter has changed their specs so many times over the past 12 years it is hard to keep up. Many tile me are told by their local rep they can do this and that but in fact the printed instructions differ. Tell a man to re-check and he can get pissed off. Again it is so easy to confirm my words. Call Schluter and ask for your local rep's number. Ask him for an email stating it is OK to use drywall and modified thinsets. See what he says. You will find that what is giving by email and what is said in person is often two different things, so be careful. I do not care for this and find that often I'm dealing with a "Salesman" and not a "Tradesman". I prefer talking with the techs and the building inspectors - these are the people who know what works, what doesn't and do you really want your information from someone who makes their living "Selling a Product".
Building a shower is so different every time but the same principles come into play.
Deflection of the floor and walls.
Time line of the install.
Tile and setting materials you wish to use.