I just knew they were going to come in and do that. They're scrambling to placate you. Why would they suddenly do this? Because you complained??
That green board is not suitable for a shower, and that product should NOT, NEVER be applied onto green board. It's clearly states on it's technical data that it shouldn't be used in showers. EVER.
Aquadefense can go over gypsum board, but only in "approved areas".
Building code (IRC, etc) prohibits using paper-faced gypsum board products as tile backer boards in showers and tub surrounds, even if the paper facing and the gypsum core of the wallboard are moisture resistant.
I've posted a slew of links and info for you to educate yourself. up to you if you want to read all of them. You really should.
Notice,,it specifically says, "cementitious or masonry" and the last bullet,,,it's not a vapor barrier. so moisture will still penetrate that blue stuff into the green board. Is there a vapor barrier behind your green board? like tar paper and plastic sheeting over your studs? if not, moisture will still get through. You still have NO waterproofing. the green board lays on the wood studs. if the moisture gets through and wets the green board, and it's sitting on the wood studs that hold up your walls, what do you think will be the result in a few years?
AQUAFIN®-2K/M
Flexible Cementitious Protective & Waterproof Coating/Membrane
Technical Datasheet
Typical Applications:
Above or below grade exterior applications.
Horizontal, vertical, or overhead applications to concrete, cementitiousoverlays, masonry, brick and parging (render).
Above grade block (CMU) and concrete substrates as a waterproofingbase coat under stucco/texture coats.
Breathable (not a vapor barrier)
https://www.aquafin.net/us/en/files/aquafin-2km-86218875-c865-4f30-8113-2c7ef4285236/TDS_Aquafin-2KM%20100219.pdf
Look, right now these guys are scrambling for damage control and hoping you won't know the difference.
Go look up the specs for green board. Go find the part that says, "green board can be used in wet areas and can be coated w/waterproofing membranes." I already know what it says but I'll wait here for you to find it. (i'll save you the time. It doesn't say you can do it)
right here they talk about using the aqua stuff over green board. ALL of the pros there say nope. not approved. and mold will eventually become an issue. is that what you want?
https://www.johnbridge.com/vbulletin/showthread.php?t=121980
Most of the manufacturers of direct bonded waterproofing membranes will tell you, in a candid moment, that their products will work quite well over a gypsum backing board in a shower, they just can't publish that due to the current code restriction on the use of such gypsum products in wet areas.
Shower might last a long time if the work was done well, but it's still not an acceptable installation according to building code and tile industry standards. The junction of the gypsum board and the tub is the most likely point of early failure and the place where your installer probably didn't do what would be necessary if he wasn't even aware that the MR Board wasn't correct for the application. (Meaning, all those places that weren't taped, and where silicone caulking was not used)
And what about all the other goofs? nothing was taped and mortared. (not that it matters because this substrate is not suitable for a shower!
please read this link as to why:
https://www.johnbridge.com/vbulletin/showthread.php?t=126842
Is Greenboard Allowed for Wet Applications?
another dilemma w/greeboard
https://www.johnbridge.com/vbulletin/showthread.php?t=80491
I'll say it again. You're getting hosed and they're taking advantage of you. the shower was built incorrectly. a year or two down the road when it begins to crumble and mold overtakes the bathroom, do you think they will come back to fix it for you? You're paying to have a shower tiled correctly. why should you pay for something that is doomed to fail and possibly be hazardous to your health? Not to mention the other issues w/water seepage that could occur to the rest of house.
I've, We've, given you all the information. Up to you what you do with it.
Q
old kitchen
Q