Well, I have to preface this by writing that I don't use any of the GP gypsum core or Dens-anything products in wet areas.

But the last time I saw DensShield, it was a gray panel. Now the color could be off in your photo, however, that looks like regular ol' green papered moisture resistant drywall. Unless things have changed recently, MR-drywall has not been approved as a tile backer board in a wet area even when covered with RedGard.

Here's a link to RedGard installation instructions. Two things:

1) Note that under Suitable Substrates: that gypsum board is not listed a suitable substrate for RedGard. Understand that "Gypsum based cement topping" has nothing to do with drywall or any type of gypsum panel.

2) Note that under RedGardî as General Waterproof Membrane (ANSI 118.10) that from your description he is treating the seams properly: Applying RedGard into the joint, then fabric over the RedGard, then more RedGard to smooth it all out.

RedGard normally isn't used over DensShield because the face of Denshield itself is water impermeable. That's why the DensShield instructions would have you thinset and mesh tape the seams.

With all that written?

If this is RedGard over moisture resistant gypsum board or "green board", I'd have it ripped out. Green board as a tile backer board in a shower is a code violation.

If it's RedGard over DensShield, then I'd say no worries. The RedGard and fabric seams will be more protected from moisture than the thinset and mesh taped seams.

It's your shower, so you could call GP tech support and ask them about RedGard over DensShield to get a warm fuzzy. If you do, I'd love to hear what they have to say just for future reference. If it is DensShield, make sure all seams get fabric and RedGard, and that any remaining exposed panel edges and fastener heads are hit with RedGard to seal them. You don't want moisture getting into the core of the DensShield panel.

Good luck!

Mongo - thanks a lot for replying

I can confirm that the wall panels are indeed Dens shield - I found a left over piece and saw it written.

I actually just got off the phone with both Dens shield and Redgard in regards to both of their products

Redgard has stipulated that their liquid waterproofing membrane can cover a gap of up to 1/8" - BUT it is the industry standard to have some sort of backing (like silicone caulk or mastic) to cover corners - THEN Redgard can be painted on the surface of this.

Dens shield has also confirmed that for all corner intersections that there should be a MINIMUM of a silicone caulk in their corners or changes of plane, THEN Redgard can be painted on top.

As per Dens shield instructions though, the usual way they handle corners and seams is to caulk, tape and thinset (its in their installation instructions) in that order. Then Redgard may be applied last

Thanks for posting this. Going through the same thing. Any tips that you would like to share after the fact?