I'm getting ready to do a preslope in my shower base. While looking for a mortar mix at my local home depot. I found two products. One actually states for use on shower pans. It costs $15 for a 40 pound bag but has the look of a consistent grey dust. It states that it is rock hard in 1 hour. The other is $4 for a 40 pound bag but you can actually see the sand in the mix, as in Harry's pix on this site. Is anyone familiar with which product to use. Am I better off using a latex additive as opposed to water. I only expect to spread it from "0" to 3/8 of an inch.

If you're spreading it from 0" to 3/8" then the sand-mix won't work because it doesn't "spread" ... it requires thickness for it "packing" characteristics.
I don't know what the other stuff you mentioned is, but maybe just a bag of thinset mortar will work for such a thin application.

The only reason I ever use latex additive in my mortar beds is for when I have to feather down to anything less than 3/8" which is usually around the drain flange. Even then it isn't a requirement. Water works fine.

The reason I'm going down to "0" is because the drain is already set at ground level on a concrete floor with room allowed to adjust up enough for a couple of inches for finishing base. I actually had someone come in and set it and put in a membrane. after some research I found that it should have be presloped which he didn't do, so I carefully removed the membrane and will reinstall after I pitch it. Are you sure thinset will be okay and is it workable to pitch. This is my first time doing any kind of concrete or ceramic tile work, as if it isn't obvious....

Hey Harry, It's me again. The product is from a company called rapid set and can be found on rapidset.com. They appear to have a couple of possibilities. Mortar mix which they say can be as thin as a quarter inch and concrete all which can go to a feather edge. I'm just curious as to if it will flow level or if it can be pitched. I will try to contact them concerning that.
Thanks, Don

You want me to maybe do a bit more research and rethink this a bit more before I provide my final answer?


The answer to your question of being able to create a thin mortar bed which tapers from 3/8" to o" is to use medium bed mortar, dryset,thinset or just about any mortar .... even masonry-mix (mortar mix) will do what you asked. But maybe what you asked isn't the right question.
A proper mortar bed is much thicker than 3/8" .... but I'm assuming you have reasons for doing things this way.

If you're building a mortar bed .... nothing should be "flowing". Visit shower pan construction and get a better idea of what "deck-mud" is.

And remember .... tilesetters don't use the word "flow".

Just a word of caution on Rapidset..It does set up fast and you might want to use something that gives you more working time..Rapidset is like 1/2 hour..

Thanks Timmer, I used thinset. It worked okay, but even that set up pretty fast because of how thin it was. It wanted to "peel" before I could smooth it out as much as I would have liked, but it's only the preslope so I'm okay with it. Thanks, Don

OK, so now that your pre-slope in done you're ready for the membrane right? You mentioned a drain before? What kind of drain? It's made for shower floors to accept the membrane right?

Jaz