You would install your pan first, cover it with cardboard then install your cbu to where it sits on the lip of the pan. Which pan are you planning on using?

 

We’re using Schluter KSLT1930 for the pan. In your scenario doing the pan first then board, would I apply Kerdi band and kereck directly to the cement board, and then redguard over everything? Or redguard the board first and then apply the Kerdi seals?

 

Are you saving money by using Durock over Kerdi board? Curious as to why using. @jeffnc will have more insight on the Schluter stuff. I was under the impression you were using a standard pan with cbu. Wait on him to chime in.

 

I would like to use Kerdiboard for the whole project, but I’m finding nothing online about applying a microcement over Kerdiboard or membrane. If I can apply microcement over this (which is the first question I pose in the original post) I will be going that route.

 

With a kerdi pan the walls get wallboard before the pan goes in.
i have no idea what microcement is.

 

Just watched a vidio. Thats cool
They used Go Board on the walls.

 

I've never heard of microcement either. But after looking it up, my assumption would be this: it wouldn't be a good choice over KerdiBoard. However I can't see any reason it wouldn't be fine over cement board covered with Kerdi membrane. So build your shower as usual with Kerdi pan, cement board, Kerdi membrane, and the standard KerdiBand and corners. Then simply apply the microcement on top of that instead of tile.

I would call Schluter technical support to check.

 

Kerdi products are fine for microcement. Follow the directions for a waterproof application. You will use a thinset bond/base coat. Add sand to it to make it gritty. Any visible imperfections in your base coat will be visible in your finish coat so sand down, scrape or build up areas that need it.

 

What did you end up doing? I am also thinking of doing this

 

I installed cement fiber boards in the shower area, then Kerdi membrane and shower pan, followed by redguard. I just did my rough coat of Surecrete this weekend and it’s looking great so far.

 

I have redone 2 bathrooms down to studs and placed drywall (made for wet areas), sealed all corners and joins with silicone. Red guard up the walls about 12” and covering the floor (cement floor in both) then venetian plaster (one bathroom) and microcement (other bathroom) on the walls and the floors.
Both bathrooms curbless to drain with rounded edges at wall/floor intersections to make cleaning easier. The whole bathroom (again, very small) is like a big bathtub technically.
I searched the wilds of the internets to sort out the details prior but so far its been great and I would change nothing.

 

Did you have a shower pan? The floor drain is my my concern!

 

@jesssmith see post #12

 

I just had an email exchange with Schluter US cust svc. They still do not support microcement over kerdi products. They say they haven't tested it.
I can't imagine that it wouldnt work other than maybe an adhesion issue.
I have been searching online for successful micro over kerdi membrane but not much luck. Especially over time.

 

can you expound on the thinset bond/base coat? do you mean float a whole layer of thinset onto the kerdi board, let it cure, then proceed with the microcement?