Creating a pan for a single piece stone shower pan

[GGohacki]

Hey everyone-

I live in NYC and I am about to install a one piece (32x32) stone shower basin and tiled wall stall. My thought is to create a stall with Hardiboard on the walls and create a base with 3/4" plywood and a 1/4" Hardiboard. I was thinking about using Hydroban or RegGuard to create a water proof membrane, then place the stone basin and tile the shower walls. My question is this: In your opinion, with the properly installed wet membrane give enough of a waterproof surface? also, I am hesitant to slope a sub pan towards the drain because I would like to have a solid, flat base for the 155b stone (I don't want it to crack). Your thoughts are much appreciated.

 

[Jadnashua]

Is the stone 'real' stone, or is it manufactured? What do the installation instructions say? Some of those things are waterproof, but not all. Some require a secondary waterproof liner, some don't.

Properly installed, liquid waterproofing is waterproof. The harder thing is getting the wall/pan junction waterproof. You could use something like KerdiBoard or WediBoard and their sealant to bond it to the pan, and the whole thing would be waterproof quickly and easily. Lots easier than a cbu, taping and filling the joints, then adding waterproofing on top. If you do decide to use Hardiebacker, you need to hold it 1/4" up off of the lip of the pan, then try to fill and waterproof the gap. HardieBacker is a fiber-cement product (contains cellulose to stiffen it), and cannot be in contact with the pan. IF you use a different version, you could make the gap smaller or have it in contact with the pan. There are essentially two classes of cbu's: fiber-cement, and cement. Each has it's own installation requirements, and they are not the same.

Most single piece pans do not use a clamping drain, which is typically what is required to use a waterproof liner. Plumbing code requires the liner, when used and needed, to be sloped to the drain, which makes setting a flat manufactured pan on top of it problematic.

Without more information, can't help any more.

 

[Sponsor]

 

[GGohacki]

Hey jadnashua-

The stone is real stone. It's a singular piece of basalt. The manufacturer claims that it is waterproof and the install instructions are wobbly at best. I guess I am trying to chomp with the best option to use it as I am kind of tied to the stone now (though I am happy to be using it). My initial thought was to make a waterproof enclosure around the pan and place it in the closure. This would have the backerboard being outside of the pan, not on top of the pan. I was thinking I would have the tile be the surface on top of the pan. I see the advantage to having board 1/4 inch over the pan, but I would then worry about that seal between the pan and the board. What do you think about this?

I appreciate your thoughts.

Geoff

 

[Jadnashua]

Most natural stone tends to have natural defects, and can absorb moisture. Some stones are so dense, that they won't. There are products that are designed to provide waterproofing across a gap, but most are limited to 1/8" or so.

You might want to run your questions by the people at www.johnbridge.com . They deal in tile and showers exclusively - lots of pros there. Terry's site is great for plumbing issues and there's a few good electricians, but rarely numerous tiling professionals to get a bunch of viewpoints.