– Zoom on the walk-in shower
– Step 1: Position the drain plug
– Step 2: Make a form for the drain
– Step 3: Pour the bottom of the shower tray
– Step 4: Install the drain
– Step 5: Install the waterproofing sheet
– Step 6: Cut out the drain grate support
– Step 7: Make a diamond point screed
– Step 8: Lay the tiles
Aesthetic and discreet in the bathroom, the walk-in shower is becoming more and more popular. Spacious, accessible, and decorative, it requires great attention during its construction, especially to the drainage of water and the waterproofing of the whole at the risk of significant disorder.
There are two main methods to build an Italian shower:
– the installation by making the screed yourself;
– the installation with a ready-to-tile shower tray.
This sheet presents the first method, i.e., the realization of a “masonry” Italian shower.
Zoom on the Italian shower
The walk-in shower is a shower space on the same level as the floor. There are two possibilities:
– Either the tray is embedded in the thickness of the floor, which must be at least 15 cm.
– Or the installation is done with an Italian shower kit including an extra-flat tray, which will allow the tray to be integrated at floor level, in the bathroom covering (tiles, parquet …).
In new buildings, a reserve is generally provided for the installation of the shower tray, whereas in renovations, three options are possible due to the absence of a reserve:
1. Raising the shower with a small step, but it is no longer a “real” walk-in shower (even if the tiles can be identical in the shower area and on the bathroom floor to ensure aesthetic continuity).
2. Raising the entire floor of the bathroom with waterproof chipboard.
3. Digging out the slab by at least 12 cm. This is quite a lot of work to do.
Good to know: it is evident that digging the floor afterward is complicated and requires a base with a thickness of at least 15 cm. The easiest thing to do is foresee the hollow that will support the future shower tray when the concrete slab is poured.
1. Position the drain plug
– Locate the drain on the floor by marking it with a cross with a felt pen. You can position it in the middle of the future shower tray or close to one side of the wall.
– Position the drain on the cross and check the existing slope between the drain pipe and the drain with a spirit level and a meter: a slope of 2 cm/m (2%) is required for a walk-in shower. If necessary, place a wooden wedge under the drain to increase its height.
Good to know: Water drainage is an essential element in a walk-in shower because of the absence of a rim. Thus, if the diameter of a drain is generally 60 mm, it is necessary in the case of a walk-in shower to install a drain with a diameter of 90 mm.
2. Make a formwork for the drain
Before pouring the first cement slab, it is necessary to reserve the drain’s location and its connection pipe to the drain.
– Make a wooden formwork with pieces of wood and nails, taking into account the necessary height.
– Put the drain back in place.
– Check the height of the drain and the slope of the drain again. This will give you the height of the screen to be made.
– Mark this height on the wall all around with a pencil.
Tip: To make it easier to remove the formwork, lubricate the outer part of the formwork with oil or lubricant.
3. Pour the bottom of the tray
The bottom of the shower tray will be made of concrete, so it is necessary to prepare it.
– Mix the concrete (preferably fibered) with water in a trough (or wheelbarrow) in the proportions indicated on the bag.
Use the marks you made on the walls to get a flat concrete.- Pour the concrete with a bucket all around the formwork.
– With a trowel, level and smooth the surface of the concrete that should reach the top of the formwork.
– Let the concrete dry for about 2 days (48 hours).
– When the concrete is dry, remove the formwork with a hammer.
4. Install the drain
– Position the drain in the reserved area.
– Check the slope of the drain with a spirit level again.
– Position the PVC pipe between the drain and the plug to determine the required length.
– Cut the PVC pipe to size with the hacksaw.
– Deburr the pipe with sandpaper. Degrease the ends of the pipe with little methylated spirits soaked on a cloth.
– Glue the tube to the bung with PVC glue, then to the drain pipe.
– Let it dry.
– Test the water tightness of the assembly by running one to two liters of water through the drain.
5. Install the waterproofing sheet
– Mark the shower walls at the height of 10 cm from the screen with a pencil, a ruler, and a level.
– Remove the grate support (upper part) from the drain.
– Spread the waterproofing sheet on the screen, letting it overhang the walls in a roughly balanced manner.
– Locate the drain hole under the tarp and cut it out at this point so that the drain grate can be replaced later.
– Place the overhang on the walls and mark the height on the tarp that corresponds to the level of the marks previously made on the walls.
– Cut the excess of the tarpaulin on the walls with a cutter.
– Glue only the part overhanging the walls with PVC glue. Be careful; the part of the tarpaulin on the floor should not be glued.
– At the corners, cut the tarpaulin and fold it on itself to complete the waterproofing. This is called a “handkerchief fold”.
Good to know: there are kits where the drain is already integrated into the waterproofing sheet. In this case, it is not necessary to cut the liner at the bunghole.
6. Cut the grate holder from the drain
– Put the grate holder in the drain hole.
– Place the level on the bathroom floor and point it towards the grate support with a slope of 2% (2 cm/m).
– Mark the grate support with a felt-tip pen. This mark indicates the height that must be cut off the grille support to be correctly positioned with the 2% slope.
– Cut the grille support with a hacksaw and deburr it.
– Oil the O-ring and replace it on the grille support.
– Reposition the grate support in the hole of the drain.
7. Make a diamond clevis
To ensure water flow, you must make a diamond point capping that will naturally lead the water to the drain.
– Mark the height of the bathroom floor minus the thickness of the tiles on the edges of the waterproofing sheet.
– Prepare a batch of dry mortar.
– Pour it on the waterproofing sheet around the grate support (which you have protected beforehand so that the mortar does not enter it).
– Smooth the mortar down to the marks you made on the waterproofing sheet.
– Allow the grate support to protrude as far as the bathroom floor tiles. This will allow for a better view of the slope.
– Check that the screed is level around the edges and make the diamond slope with a trowel. To do this, mark the diagonals between the grid support and the corners of the receiver with the tip of the trowel.
– You should have four planes with the correct slope (2%) in the shape of a triangle with the points meeting at the drain.
– Smooth the mortar with a pointed trowel and let dry for 24 hours.
8. Lay the tiles
– Lay the wall tiles all around the shower tray, gluing them to the waterproofing sheet that extends over the wall.
– Lay the floor tiles, starting with the full tiles on each “triangle” of the tray, then complete with the half tiles cut into a triangle using a tile cutter.
– Let dry for 24 hours before grouting.
– Assemble the entire drain: grate, debris cover, dip tube…
Materials to make a walk-in shower
|Hammer||Starting at $4|
|Tape measure||Starting at $4|
|Spirit level||Starting at $4|
|Hacksaw||Starting at $15|
|Trowel||Starting at $4|
|Pointed trowel||Starting at $3|
|Tile cutter||Starting at $20|
|Bucket||Starting at $1|
|Trough||Starting at $2|
|Wooden boards||According to species and dimensions|
|Rubbing alcohol||$3 approx.|
|Sanding paper||About $5 for 3 sheets|