Tile contractor Tom Meehan: On the outside walls I can use mastic or thinset, but since this is a waterborne area—an open shower—I’d rather use thinset on the bottom half and mastic up on top. Thinset is a little more difficult to use, but it repels water tremendously. I use the back side of the trawl to burnish the thinset into the backerboard. That gets a better bond. Then I come across with the notches, which score the tiles.
Now that I’ve spread the wall with thinset, it’s time to start tiling. I center the first tile on the plumb line. With each piece I put in, I give a little push to the left and right to get good contact. I do the top two courses and then I put my long level on it. If there’s some fluctuation, this is the time to push the tiles in place. Once the starter courses are done, I continue with the field tile. The complicated cuts I leave for later on, but for the tiles around the pipes, I cut them now. Around wires and pipes, I don’t cut the tiles perfectly tight because the plumber or electrician may still want to do a little work. Because there will be a trim plate to go around the pipes, I give the tiles a little bit of play so that it won’t be difficult for someone else to do what they have to do.
There are three different ways to approach the outside corners. With a 6-inch bullnose, I can cut it down. There’s also a 2-inch cap, which is a bullnose. Many times the shade of the 6-inch bullnose is a little different because it’s fired at a different time than the field tile is. Also, if I’m going to change the tile pattern to diagonal on the top half of the wall, then I can’t carry the bullnose all the way up the wall. A 2-inch cap just doesn’t work here. Instead, there are these great strips that come in different colors and finishes. I’m going to use this because I can maintain the same look all the way up the wall. The strip just embeds in the mud. I run a piece of tile along the back side as a depth control to make sure the overhang is just right, because I will tile right up to the strip.
Now what I’ll do is cut these tiles right into the edge of the strip—the perfect finish piece. As I put this tile in, I put the cut edge up against the molding, not against the field tile. The field tile has a rounded edge, and if I ran the cut edge against it, you would see a jagged, sharp edge. After I cut the first two, I make sure they fit the whole way down, because many times the bottom will flare out and the size of the piece will vary. And it does here, so I’ll adjust the cuts as I get down to the bottom of the wall. Where the pieces will overlap the molding, I back-butter them to get good contact.
When I reach the bottom, I put a cut mark on the back side of the tile and transfer the mark to the front side. After I cut the first bottom tile, I check the fit in a few places. It seems pretty consistent. The larger tiles plane out a little bit higher, so when I cut the smaller pieces and put them in, I butter them up a little bit so that I can get them in the same plane as the large tiles.
Now it’s time to lay out and install the glass mosaics. Start at the centerline and mark off each course. Keep the glass mosaics taut, so the layout is accurate. Glass tiles should only be set with glass tile adhesive or thinset. When I first apply the thinset, I burnish it into the cement board. Then I go over it with a notched trowel to raise the ridges, and then I flatten down the ridges so that they don’t show through the translucent glass. At the end, I cut the band into double strips so that they remain perfectly straight to the human eye. To plane out the small tile, I use a good rubber float and press that in so that any high tiles will sit flush with the rest of the tiles. Once everything is set, I use the straightedge along the top of the glass mosaics to make sure everything is very crisp.
Once I’m done with the glass band, I’ll move up to the upper walls and do all the diagonal tilework.