To make this interesting for the casual reader I will try to highlight the main points and allow the photos to do most of the “talking”. I have five tile-cutting tools at my disposal!
I face a special situation – the bathroom floor must be in the same plane as the engineered hardwood floor in the adjacent room. To accomplish this I use what is known as a decoupling membrane – a ¼” thick mat laid in a bed of mortar. The mat isolates movements between the subfloor and tile. As the photo shows, I’m in the process of laying a thin bed of mortar on top of the decoupling membrane, yielding a smooth surface for the mosaic floor tile to follow.
Lay-out is an important first step, and I pay lots of attention to it. I want evenly spaced borders, while minimizing cut tiles. A sloppy laid-out job hurts my eyes!
Vertical and horizontal lines are established with the aid of a laser level. Most often I need to maintain an accurate horizontal line. Vertical lines are of secondary importance. As the photo shows, these 3” x 6” subway tiles are installed in a brick-like pattern. Horizontal lines are continuous and vertical lines are “broken”. The plywood supports (photo) are held in place by ultra thin brads, and support the starter row and those to follow. The tiles just above the tub are custom fitted and installed last.
The photos show membrane protection on the walls and, especially, the flat storage area above the shower/tub. I could have used a waterproofing paste. The use of paste ensures that I have an absolutely flat surface on which to lay small tiles. A membrane on the other hand, offers superior water protection, but it requires that I tile over laps in the membrane system. This can become problematic with small tiles. As a rule, I prefer to use membrane material to protect the wall areas in direct contact with water.
Tiling out of tight spaces
I plan my work so that I am not caught in a tight spot! I wish to avoid walking on freshly-laid tile. I make layout lines near the middle of the room, so that slight variations in tile spacing don’t accumulate and cause problems near the walls. I lay a dry bed of tiles (with spacers) down the length and the width of the room, making appropriate adjustments. Then I snap chalk lines. I screw a long, absolutely straight metal bar to the floor, and lay my first row of tiles in a bed of mortar, against this bar. Now I screw another guide bar to the floor at right angles to the main bar, and lay another row of tiles. Now I am ready to work the first quarter of the room, with ample space for my aching body, my tools, mud and clean-up buckets and tiles.
This is where the fun begins! I want my grout lines to be perfectly even! Glazed tiles require the use of masking tape (be careful with a permanent marker), in order to make crisp pencil lines. After the tile is cut, I fit and “sand” it to perfection, using a battery-operated cutting tool. The cut is rounded over lightly, to mimic the edge of the tile.
A shower pan
CAUTION – This work must be done right, or a slow leak may cause structural damage! A leak is hard to find and harder to repair. For technical reasons I do not recommend using the Kerdi-Schluter kit.
I lay the shower floor base (made of dense foam) into a bed of modified mortar. This material is factory sculpted to channel water to the central drain. My kit of choice covers a 3’ x 4’ area – half of the shower floor. The rest is covered with a sheet of dense foam, laid in a thick bed of mortar; slightly sloped towards the drain. I install the drain assembly. Next I install the water proofing membrane on top of the foam, then on the walls. Membrane components must overlap.
I want more slope on the far end of this walk-in shower, so I mix mortar and quartz sand to a fairly stiff consistency, and lay a thick, tapered bed on top of the membrane. I apply fiberglass mesh and, with the aid of a level, I create the desired slope.
The key to a water-tight installation is to apply the various shower components in their proper sequence. The shower curb (dense foam) is installed last. I custom size it to match the tiles that cover it. The photo shows the curb in place and the shower floor pitched towards the drain. Now tile work can begin. First the floor, then the walls.
Laying mosaic hex-tile on the floor
I am extra careful with my layout, taking wall tile thickness into consideration. Since the shower floor slopes multi directionally there is a chance that the tile pattern will become distorted near the shower drain. I lay the tiles and deal with problem spots the next day, before the mortar has completely dried. This means prying out a few tiles and re-setting them.
It is imperative to work cleanly, keeping the mortar out of tile joints! I let the tiles set a few hours. Then I lay a small sheet of plywood on the tiles (to distribute my weight) and clean the joints carefully with a stiff brush. The final cleaning is with a sponge. I am careful not to distort the tile pattern while I clean.
I wait a couple of days before grouting, because the mortar bed on top of the membrane needs plenty of time to dry and cure. I grout the joints. Sometimes I find pinholes in 1/8” grout lines, so I make a habit of checking my work and re-grouting as needed. When cleaning freshly laid grout lines it is important to keep the grout sponge as dry as possible, since excess water can cause blotches.