That's the first time I heard of "green eboard". Thanks for the heads up.

I did Sheetrock behind kerdi on the first few kerdi showers years ago but switched to cement board. I just feel more comfortable with the install. I know my own drywall kerdi shower is still doing fine and it's been over 10 years.

I've used drywall and cbd,too. I prefer the cbd. If there is a plumbing leak you could have the drywall fail. Cbd would survive.

Also, for towel bars or other penetrations, cbd is stronger imo.

Is Durock or Hardi and a modified thinset to embed the Kerdi preferred or sheetrock with an unmodified for embedding the Kerdi?

Chevy, No Modified Thin-set with Kerdi, I use Kerdi Board Myself.

I wouldn't use a substrate that would promote mold growth or would fail in the face of a plumbing leak regardless of what others or any book says is acceptable.

I use cement board.

I like densarmor. I'm not a fan of cement board.

Green Eboard is made in China. They can keep it. I use Permabase and AquaDefense for walls.

DensArmor is my favorite for ease of use but it's hard for me to get so I mostly use Permabase. Durock is about the same. I'm not a fan of Hardiboard. That dust is brutal.

I used densarmor once. May try it again. Seemed a little more consistent in thickness.

Plus the screwing and taping it with Fibafuse is a heck of a lot faster than with the cbu. Just remember to wear gloves. DensArmor will tear your hands up pretty badly.

I have always preferred CBU over drywall. I've seen the effects of water leakage on the back of drywall where CBU would have stood up.
That being said, I have been using more and more Wedi over the last year or so and like it as well.

I don't have any problem believing that drywall should be OK, but it just feels wrong. I do condo work where due to fire rating the drywall is going to stay, but I still put on 1/4" Hardi.

We have recently started using Fiberock on shower walls due to the fact that it is the same thickness as drywall, where 1/2" Hardibacker is not. The Fiberock is easier to cut than hardi as well. Still makes dust, but not near as bad as Hardi. Once it's hung, we red guard everything and tile it.

What’s the difference between DesArmor and DensShield?

DensArmor is drywall with no paper content 4x8 sheets. DenShield is tile backer 3x5 sheets. Personally not a fan of either, and haven't seen any at local suppliers for years.

Would it not make sense to put a “tile backer” behind tile? I’m just a simple kinda guy.

That's what we do. Haven't ever put Sheetrock behind tile. Boss would probably try to slap some sense into me (literally) if I suggested it. Not that I would, because I'm just as passionate about the quality of work we do as the boss is.

Im with Angus. I use Permabase but with Hydroban.
Easy to work with and priced right.

Schleuter insists that standard drywall is sufficient. I have done green board and it worked fine. Heck I did showers directly on too of green board years ago before I knew any better (showers in my dads rentals) and they are still standing. That said I have since honed my craft and I am particular to cement board. As mentioned earlier drywall with disintegrate in the instance of a plumbing leak whereas cement boar will survive. Also hardibacker is great for floors but wicks water so I would never use it in a shower.