How you create or build a shower curb depends a lot on what the builder likes to see. Me - I like to bond my waterproofing directly to the shower curb so I prefer a concrete curb. Not one made from wood but one made out of nothing but concrete, bricks, thin-set and concrete board or CBU sheets.
A simple concrete curb can be created by setting bricks down to the sub floor or cement slab. Then covering them with concrete board to create the final shape.
Here is an example showing a simple method.
The bricks I sat one day prior to the day I took this photo. The bricks are old commmon ones. Grey. The came from my home renovation, and where part of my old chimney. I set them in place with some Ardex X5 thin-set. Some gaps. Lots of broken pieces. The bricks are a mass - something to build off. Nothing more. On the shower side I set a piece of 1/2 cement board with some more X5. Then I went home.
The next pass I filled the large gaps in the bricks with Ardex X32. This thin-set designed for thicker applications. You can see Ismeared the thinset into the voids and onto the back of the front cement board. The height of this piece I made about a 1/4" taller than the inside. I want a sloped top - sloped to the shower.
I then added a cement barcker board to the top in the same fashion and wrapped the curb with my mesh reinforcing fabric. I use Mapei's HPG Lath for this step. The thin-set for this step the same X32 I had mixed for setting the CBU pieces to the bricks.
This curb will not swell if it gets wet. It will not move if it dry's out. It will not shrink like green wood lumber and will hurt your foot if you kick it. It's concrete. It's rock solid. You can waterproof directly too it.
More info and planning for shower curbs can be found on this Houzz Resource: [How to Build a Better Shower Curb[(https://www.houzz.com/magazine/how-to-build-a-better-shower-curb-stsetivw-vs~4142945)
url: https://www.houzz.com/magazine/how-to-build-a-better-shower-curb-stsetivw-vs~4142945
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