Under a curved curb

[zDotEnergy66]

I have inherited a tile job in volunteering to help a friend whose tile man has vanished and cannot be found. It involves building up a curved curb so the curved glass panels and door can sit on top of it. The existing floor is concrete which had vinyl tile glued to it - some of that tile was removed, but some it is so stuck that is being left in place to be covered. I plan to use self-leveling mix in the main floor area outside of the shower.
1. Is it ok to build up layers of (exterior?) plywood cut with the curve to then be covered with wire mesh and sand mix as a base for the curb of the pan? And do I need a Tyvek or similar separating layer between the plywood and the wire mesh (to prevent sand mix grabbing the plywood)?
2. I don't want to use a pan liner, and would prefer a brush-on finish as an under-mortar waterproofing. Yes/No?
3. The previous contractor installed a shower drain with two parts, which I believe is typically for use with a pan liner. Must I use a pan liner in this case? If so, how far up the wall and curb should the liner go?
4. How long must the curb sand mix base cure before tile-setting mortar can be applied and tile set?

Advice on anything pertinent to a good quality outcome would be greatly appreciated.
Thank you,
George

[John Bridge]

Hi George,

I don't see the need for plywood or lath is you're going to brush waterproofing on the surface of the curb. You should use bricks or chunks of cement block and mortar to form the curb. Takes some expertise.

You should switch the drain to a surface membrane drain. There are a number of them on the market. My fav through the years has been the Schluter Kerdi-drain. www.schluter.com

[Davy]

George, you can use a paint on membrane as a pan liner and install your mud bed over it using the drain you have. I agree that since you have a curved curb, the paint on membrane would be easier. Here is a link.
https://www.custombuildingproducts.c...5809/CB414.pdf

If you're going to have to make the curb fit the radius of the glass then make a template of that radius out of a sheet of plywood the width you want. Usually 4 to 6 inches. Place the plywood radius down and mark the floor, then build the brick curb inside the radius lines. Once the bricks are set, I would then set the plywood radius on top of the bricks and use it as a guide to mud the curb over the bricks. Let that set, then you can apply the membrane and fabric over the mud.

The width of the curb can be made whatever you need for a piece of slab or pie shaped tiles to fit. Like John said, this will take some expertise.

[zDotEnergy66]

All good info. Looks like I will use a pan liner after all, since it's what my buddy wants. Meanwhile, thanks for the tips on building up the curved curb.

[Kman]

George, you're going to find it difficult to make a PVC liner fit to a curved curb. It's going to have to be cut every few inches to keep it from wrinkling up.

Maybe you can talk to your friend about the pros of using a sheet membrane or liquid waterproofing.

It would seem that the sheet membrane would have the same problem, but it's much thinner, and able to wrap corners and curves much easier. It'll require some cutting, but it'll work down much better than 40 mil PVC.

The liquid membranes will go on without any issues around curves and corners, of course.

[CaliGrown]

Agree with KMan. Liner’s not impossible but may give you headaches depending on the how sharp the angles of your curved curb are. I’d lean to doing the divot method of your not changing the drain, or get an adapter kit for a fleece bonded drain and use a topical cementitious waterproofing membrane. 3:1 mix would be good for free forming a curb straight outta mud. (Mix Credits are all mud-meister Jerry’s)