The most important part of the entire shower project to get it right is absolutely the floor pan!

And unsurprisingly, this is where most DIYers make a mistake, try to take a shortcut, or just get it wrong. Improper floor pan construction can lead to leaks, of course, but also mold growth under the tile and mortar bed if a proper “pre-slope” is not installed. But, I don’t want to get ahead of myself, I’ll cover all the details on how to do this later in the article. Let’s start here: What is a shower tray?

The term “saucepan” originates from when contractors used to install a copper saucepan at the base of where the shower was being built.

The before “:

The use of the copper pan switched to using a 4 pound lead sheet (it weighs 4 pounds per square foot, which gives it that name), because it is very malleable and can be easily molded on site. A contractor could measure the size needed, go out to the garage or driveway, fold the corners as needed with a 2×6 and a rubber mallet, folding the corners over each other and overlapping them so that all edges are on. the top. Weighing in at 4 pounds per square foot, it was quite difficult to carry around the house, but it could be done with two people and it could fold back on itself, as it is very malleable, to traverse narrow hallways and turn corners.

Using the rubber mallet again, they hammered an impression of the drain into the lead, making a mark to cut the drain hole. Once the hole was cut, the drain flange could be fitted, making a tight seal. An adjustable shower drain was then threaded onto the flange and gravel was placed around the drain holes to protect them from the deck mud that was installed next. The deck mud is a dry cement, moistened enough for the cement to hold its shape, allowing it to pile up to create the necessary slope for the water to flow into the drain.

The “Pre-Pending”:

This is where many who take on the task of building their own shower, without any experience in doing so, get it wrong. The pre-slope is a slight slope of the floor that drains into the shower drain, created with dry-pack cement. before installing the shower tray. Despite what you may think, water can and will penetrate through tile, mortar, and concrete above the shower tray, all the way to the shower tray. In the absence of a pre-slope under the shower tray, the tray will lie flat on the surface of the floor, preventing water from the concrete from seeping down and into the drain holes of the shower drain. When concrete remains wet, mold growth will occur over time, eventually causing considerable damage.

To create the pre-slope on a plywood surface, you first need to lay a layer of felt paper (isolates the concrete from floor movement) and then staple a layer of metal batten. Mix cement with enough water to hold the shape and apply creating a 1/8 “thick slope in the drain, towards the edge of the shower at a slope of approximately 1/4” per foot. On a concrete floor, no felt paper is needed, the concrete can be applied directly to the floor.

Some point between “Before” and Now:

Working time was greatly reduced when the use of vinyl membranes replaced the old lead pans. It can be easily rolled out, molded in place in the shower, folding excess siding over itself at the corners, folding over the curb of the front shower, and using a CPE bonding adhesive (in a can like PVC cement) to seal patches at the corners. A newer type of tiled shower drain was used with the vinyl membrane, like the one shown to the left.

The rubber membrane must be wrapped in the wall NO LESS THAN 3 INCHES above the intended final height of the shower threshold (curb or dam). Before wrapping the membrane on the side walls, install 2×10 board pieces between the studs to provide solid support to the siding and places to nail the siding to the wall. Nails or other fasteners should not be used anywhere except along the top perimeter of the tray liner to prevent eventual nail hole leakage.

After the tray liner is installed, the metal slat can be wrapped around the shower curb, which is made of 3 2x4s nailed on top of each other creating a 4.5-inch high sill, and cement packed into the slat and on top. of the same, giving shape to the concrete in a smooth and square surface on which the tile will be applied.

However, I always take an easier route and use the Kirb-perfect Product Made by Mark E Industries – A plastic product that easily assembles to form a cage around the lined shower sill, rather than the metal slat.

The concrete board, 1/2 ″ thick 3′x5 ′ sheets, can be measured, cut and installed on the walls with weather resistant screws (to prevent rust stains from passing through the grout later on, as normal screws rust). The concrete board should be installed leaving a 1/2 ″ gap between it and the pan siding, pressing the wall siding against the studs and 2 × 10 boards.

The actual concrete slope:

Once the threshold is finished, create the concrete slope within the shower liner, taking care to make the surface as smooth and even as possible to allow the small tiles to be laid better when laying the tiles. A chalk line can be made around the concrete board on the walls for a guide line, giving a slope of approximately 1/4 ″ – 1/2 ″ per foot from the adjustable shower drain to the shower walls .

Again, I take the quicker and easier route, using Mark E’s Quick Pitch Kit, which includes a plastic ring to place around the shower drain (protects the drain holes from filling with concrete), and sticks Inclined plastic rings that fit into the ring and are placed around it to radiate towards the corners and sides. They can be easily cut to the desired length with tin snips or a hacksaw. This gives me a perfect tone every time, and fast!

Now: the next system most people will transition to:

There is absolutely nothing wrong with the method I have just explained to you. It is still used by most contractors and is the least expensive route at this point. However, as you probably know, new technologies appear every year that revolutionize the way things have been done in construction for decades and centuries.

A system that I use now, when owners have a bigger budget, uses products made by a German brand called Schluter. They have competitors in their market, but they have led the way and own the majority of their market share. All of their products work together to make a completely waterproof shower and can be installed much faster than the previous system just explained.

Schluter contends that even if you properly install a shower with the old system as I just described, the water can still remain in the concrete for an extended period and cause mold problems. With their system, the floor and walls are waterproofed with a plastic membrane and there is no exposed concrete to absorb water under the tile. The water that passes through the tile will drain directly along the plastic membrane to the drain.

Is that how it works:

First, once the plumbing and everything else is done, install concrete panels on your walls, from floor to ceiling. I buy the Kerdi shower kit from Schluter which has almost everything you need to build a waterproof shower ready to tile. The first item in the kit to use is an expanded polystyrene shower tray. It’s already built to the correct slope, all you need to do is cut the foam (easy enough to do) to fit the opening. Mix up a batch of Thinset and apply with a notched trowel to the subfloor, then set the shower base firmly into the mortar.

You can then place a Schluter bench anywhere you want, which is basically a large block of expanded polystyrene, and it can also be cut to fit the space quite easily. This is not included in the shower kit so many times I still build my own bench out of concrete and treated 2×4 boards.

In the shower kit there is a product called Kerdi, a plastic sheet with bright orange fleece straps attached to both sides. The plastic membrane waterproofs the shower and the tape provides a bonding contact surface for the ThinSet to adhere to both sides; one side to the concrete board wall and tile on the other side.

Apply 3 ″ wide Kerdi Strips to all corners with ThinSet. After sealing all the corners, apply Kerdi to the walls and to the bench if you have one installed.

A key point about applying Kerdi to concrete board walls: Mix ThinSet thinner than usual, with a consistency of pancake batter, because otherwise the concrete board will suck moisture out of the ThinSet before it sets and the Kerdi will peel immediately.

Next, insert the included shower drain disc in a generous amount of ThinSet into the center hole and glue it to the drain pipe under the floor. Then wipe off excess ThinSet that seeps through the holes around the disc ring.

Now install, with ThinSet, a piece of Kerdi on the floor, cutting a hole for the drain. Then install the included Schluter Kerdi shower curb, cut to size and fit with ThinSet. Again, this is easy to cut and install because it is also made of expanded polystyrene. Once you are ready, install a piece of Kerdi over the edge of the shower and seal the corners with Kerdi-Kereck, also included in the shower kit. Also, in the openings around the shower valves, install the included Kerdi Seal parts

Now you have the newest and best way to build a finished, tile-ready shower tray!

… But we’ll save it for the next article! Get to work!

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