Converting shower enclosure to curbless design

[nae32123]

Hi again! I have revised by plans and will be building a more standard 36 x 48 shower with curb and frameless glass enclosure. I would still like to keep the curb as narrow and low as possible, and I get the impression a thin-bed shower pan with surface membrane is the choice for that. I understand I need a minimum of 3/4" mud thickness at the drain and 3/8" per foot slope for better drainage with pebble tiles. Two questions:

1. The concrete around the existing drain from the old preformed acrylic pan is cut out and was packed with styrofoam and random stuff before. Should I fill that space with concrete or mud (or something else) and then build up the 3/4" from there? Or since I would be filling it with several inches of material, can I just slope upwards from the level top of the hole?

2. The glass company told me as little as 1" width on the curb is all that is needed to support the enclosure. Is it possible to construct the curb by packing a mold that narrow? Or would it probably fall apart?

[Houston Remodeler]

Linnea,

1- Since the hole is so small, I'd fill the bottom with dry, packed sand then fill the upper 2-3 inches with drypack. You can do this at the same time you slope the floor.

2- We often use 2 inch thick kerdi board on edge as a curb. Works well. Ceement or drypack that thin would crack when drilled into.

[cpad007]

If you can't find a strip of Kerdi-board to use (ask, beg, plead with some of the pros around here...they might slip you a slice for a nice price) then another route might be the foam curb from Schluter. It'll be a lot larger than you need (6" tall by 4.5" wide by 48" long) but it is easily cut down to whatever you want. Once you thinset it in, it is surprisingly rock solid.

[nae32123]

The foam is a great idea! Thank you guys! once I've filled in the hole, do I need to build up 3/4" around the drain above that? Or does the fresh packed mud make up the required thickness so I can pitch 3/8" per foot from the walls to the level top surface?