Capping knee wall and shower threshold with marble or quartz


  #1  
Old 10-28-20, 11:22 AM
N
Member
Thread Starter
Join Date: Apr 2015
Location: United States
Posts: 27
Received 0 Upvotes on 0 Posts
Capping knee wall and shower threshold with marble or quartz

I plan on capping my knee wall with quarts or marble of some sort. For the threshold I think I am good on figuring out the steps. But the knee wall since I am not tiling the side outside the shower I have a question on. I have watched a few videos but never see the steps of the drywall outside tile inside part. When I waterproof the shower I plan on running the the laticrete membrane over the top and on the front of the knee wall. and then a skim coat of thin-set. My question is since the membrane is put in place using thin-set but I have read thin-set should not come in contact with drywall. So for the edge below what can I do. Once the cap is put on the underside outside the shower I will hide with a piece of chair rail trim. I think that is what its called.

Knee wall top where granite or marble will go
 
  #2  
Old 10-28-20, 02:04 PM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 27,592
Received 2,144 Upvotes on 1,920 Posts
I would consider your waterproofing over the knee wall. Whatever is there will need to be firmly attached and rock solid. If the membrane is loose, can be pulled up or stretch out of place then the stone on top can move. When you glue down the stone you want it to have a good solid connection to the wood framing below.

I would not run the membrane or thinset onto the sheetrock outside the shower. There is no need for it to go that far and it makes it really, really difficult to finish that wall so it looks good. I'd either stop the membrane at the very, inside top of the knee wall so the stone can be glued right to the wood. When the tile or stone in the shower has been finished run a bead of caulk in the corner between the capping stone and shower wall to prevent any water from wicking underneath.
 
  #3  
Old 10-28-20, 04:06 PM
N
Member
Thread Starter
Join Date: Apr 2015
Location: United States
Posts: 27
Received 0 Upvotes on 0 Posts
Pilot Dane thanks for the reply. I found the picture that inspired my question...So I had watched this video and saw the cap idea. Since this will be my first shower I wanted to no have to worry about grout seams on the top of the threshold and knee wall. In this video the outside of the shower looks like drywall to me and the inside is Kerdi. I was trying to recreate something like this. Later the marble is attached to the knee wall and the threshold with thin-set. So when I mentioned wrapping the knee wall it was supposed to look like this once I put in the backer board and stuff. Or is that making it complicated?


 
  #4  
Old 10-28-20, 04:10 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,745
Received 1,210 Upvotes on 1,098 Posts
I would run the membrane onto the top and the side where the exposed wood is and then install a piece of CBU, cement board over that, tile on the inside and end, they finish the drywall side with a fancy base board turned upside down!

You would then use thinset to install the stone top!
 
  #5  
Old 10-28-20, 04:44 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Posts: 27,045
Received 1,905 Upvotes on 1,711 Posts
The photo has a mesh (expanded metal) corner bead on top of the drywall-kerdi board transition.
Something like this probably.
 
  #6  
Old 10-28-20, 04:49 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,745
Received 1,210 Upvotes on 1,098 Posts
Other thing I noticed, looks like you have a wood bench or something in the shower.

Really want to remove all wood structures, they make dense foam pieces that are better, they will never rot if they get wet, same for any curbs or niches!

You would membrane the shower then install that inside the membrane then tile over!
 
  #7  
Old 10-29-20, 10:06 AM
H
Member
Join Date: Jan 2006
Location: USA
Posts: 3,280
Received 9 Upvotes on 9 Posts
All surfaces that will be tiled including the top of your knee wall need to be covered in cement backerboard before the laticrete membrane is applied. Make sure that all horizontal surfaces like the top of the knee wall, the bench, niches and curb are slightly pitched inward toward the shower so that water will drain into the shower.

Cover the top of the knee wall with cement board right to the outside edge of the drywall. They apply the laticrete membrane to the outside edge of the cement board. Install your solid surface piece so that there is sufficient overhang inside and outside the shower so that you can apply your outside trim butted to the underside of the solid surface material. Make sure the solid surface piece is pitched slightly in towards the shower to properly shed water.

As has been mentioned, there are other ways to make a bench. Your way will work if properly waterproofed. Secure 5/8" exterior glue plywood to the framing. They apply your cement board and laticrete waterproofing. Again make sure the bench is slightly pitched toward the shower drain so that it properly sheds water. Don't want pooling water anywhere.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: