Shower Drain Without Weep Holes

[Nick V.]

Hi,

I plan to install a new tiled shower in a wood framed home, and want to use a linear floor drain in the shower stall. The shower won't have a traditional sloped mortar bed, but will instead have a pre-sloped floor that is covered with a water proofing membrane, and then have tile installed in thinset above it.

I want to use a drain made by Neodrain, its shown in the attached files, and a listing for it is here: https://www.amazon.com/gp/product/B07JMTZLVB .

However, this assembly has no weep holes at its waterproofing flange level, and the manufacturer has told me that weep holes are not required when used with thinset tile installed over a waterproofing membrane.

Without weep holes, I assume that any water that seeps through the floor grout/tile has no where to go, and that it will sit in/around the tile and thinset until it evaporates back into the room? Will that work? Is there any precedence for not using weep holes in shower drains like this?

Thanks in advance,
-Nick
Peoria, Illinois, USA

 

[Jadnashua]

A conventional shower build has the liner buried at least an inch below the tile with a layer of deck mud. Deck mud, when done right, is quite porous, and any moisture that does get underneath the tile will be 'sucked' down into the deck mud, and stop at the liner, and slowly flow to the drain. It's a first in, first out sort of system, constantly flushing itself out.

When you use a surface applied membrane that sits directly underneath the tile, the only thing between it and the top surface of your tile is some thinset. Thinset is much denser than deck mud, and most moisture that might penetrate the tile and grout will have a chance to evaporate rather than being sucked into the deck mud by wicking and gravity. So, typically, a drain designed for that type of shower does not have any weep holes and they aren't needed.

 

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[Nick V.]

Thank you Jim. This is what I suspected, and what the manufacturer claims. I wanted a sanity check from a third-party that it made sense.