There are two types of water drainage called weep holes. There are weep holes in the shower drain in the floor beneath the tile, and there are (should be!) weep holes at the bottom of the tile installation on shower walls above a tub or acrylic shower base. They both do the same thing (allow water behind the tile to drain), needed for different installations. I will address both here.

Weep holes in shower drains beneath shower floor tile

In a traditional shower floor (with a pre-slope, rubber liner, top slope then tile) weep holes are required in the shower drain. The top mud deck, or top slope (the deck mud onto which the tile is installed) will remain saturated with water (if the shower is used regularly). This is called a water-in, water-out system. Water will get behind your wall tile, and beneath your floor tile. When properly constructed your shower has the waterproof liner installed over a pre-slope, then deck mud is installed over that with tile bonded directly to it.
The water that gets behind your tile will run down your waterproofing and into the floor liner. That water will soak into the deck mud on the top slope. This is normal!
With every use, the water will flush through, with new water getting behind your tile and forcing the old water down, eventually into the drain.
This is water-in, water-out.
When unused, gravity will draw that water down toward the drain. Since this layer is below your tile, so below the top opening of your drain, that water needs a way to enter the drain. That is the purpose of weep holes in your shower drain.
Regardless of your brand of clamping drain, the weep holes will be integrated into the upper flange.
A clamping drain is called that because the rubber liner…wait for it… is clamped between the upper and lower flange, creating the seal.
Tile product manufacturers aren’t known for their originality.🤷‍♂️
This image shows the hole in the liner, centered over the lower flange (place silicone beneath the liner to help seal it). The upper flange is the black ring sitting next to it. The keyhole-shaped holes are placed over the bolts, twisted to lock in place, and tightened down to clamp the liner between the two flanges and seal it. If you look at that ring the four little channels along the edge that run inward toward the four holes are your weep holes. The water runs through those channels and down into the weep holes into the drain.

One of the most asked questions by do-it-yourselfer’s is whether they should use caulk (or silicone) or grout in the corners. Industry standards state that a flexible material be used at all changes of plane. But! – if you ask a hundred different professionals you will more than likely receive fifty of each answer.  While there are pros and cons of each, I am in the camp that uses silicone (you can use caulk). That being the case, I will discuss using grout first. I’m backwards like that.

Using Grout at Changes of Plane

While the phrase “changes of plane” may sound a bit uppity or technical – it’s not. It simply describes the corner or edge of any surface that changes direction such as a corner, a wall to a floor, or a wall to the tub edge. Many professionals simply grout that corner as they do any other space between the tiles. There are a couple of things that must be taken into consideration before choosing this method.

1. Your walls and the framing of your shower must be absolutely rock solid. I do mean absolutely. Grout is a cement-based product and as such is not meant to flex. If your wall moves your grout will eventually crack – it’s that simple.
2. The space between the tiles at the change of plane must be large enough (for sanded grout) or small enough (for non-sanded grout) to be able to support the grout. That simply means that if you are using sanded grout you cannot butt the tiles against each other at the corner and expect to be able to force grout into it. It will not stay if the grout has no grout line to hold onto – if it is simply attempting to grab onto the face of the tiles at a 90 degree angle. There must be a grout line at the changes of plane.
3. You must decide you are going to use grout at the changes of plane before you install the tile. You can then make sure to leave a line for the grout as well as adding additional support for any spots that may move even the tiniest bit (which it should not do anyway).

If you have taken the above points into consideration and still decide to use grout in the corners – go ahead. The big advantages of using grout here is that it will match all the grout lines and it will never have to be replaced. So although extra care must be taken to properly use grout at your plane changes, the advantages for some people are worth the extra time. [continue reading…]