(If you haven't already read the first section of How to Install Tile in Showers and part 2 of installing tile in showers, we recommend that you do so.)
Showers are wet areas and need to have a minimum of 95% coverage of bonding mortar when beaten in. In this case a ¼" x ¼" notched trowel provided the coverage. The thin set is then combed out in preparation to set the tile. Note that only enough area is combed out so that it can be tiled within 15 minutes. If the thin set begins to "skim over" or dry, the thin set must be re-combed or scraped off and re-applied altogether.
Place the tile in the fresh thin set bed, beat in, and align using spacers if desired. The joint on this job was 1/8". Note how the spacers are placed here. This facilitates easy removal later. Spacers must be removed prior to grouting.
As the installer progresses up the wall, the installer checks each few rows of freshly set tile to verify that the rows are staying level and aligned correctly. Periodically pull tile off the wall to examine the coverage.
Continue this process up both side-walls until the field tile is set. If there are accent strips, soap dishes, or shampoo shelves, the field tile can be removed allowing room for the items. Be sure to scrape the wall surface clean of the un-cured thin set. These photos show the cut out method for the shower valve escutcheon and soap dish.
Remove the ledgers and carefully scrape the excess thin set off the wall if present.
"Key in", comb out, place the tile, beat it in, and align with spacers. Then use duct tape to hold the lower tiles in place while the thin set cures.
The decorative strip is then installed along with the shampoo shelf and surrounding tile.
At this time the shower pan is cleaned out and vacuumed in preparation for the next steps.
The dam is prepared for mortar by protecting the adjacent floor. 15 pound roofing felt is applied to the top and front of the dam only. No fasteners are used on the top or inside edge of the dam. Fasteners are used only on the front.
(The original builder used fasteners on the top of the dam to fasten the reinforcing wire. Had there been any shower pan membrane, this would have led to its failure.)
Fashion reinforcing wire by measuring the necessary distances and pre-folding the wire to obtain a tight fit.Fashion reinforcing wire by measuring the necessary distances and pre-folding the wire to obtain a tight fit. The idea here is to have the wire hold itself in place as fasteners are used only on the front of the dam. Be sure that dam wire terminates at the level of the bottom of the side-wall tile.
Key in wall mortar to the dam reinforcing wire. Set small float strips by using a small spirit level measuring from the back-wall to keep the strips parallel and square to the rest of the shower.
Use a little dry mortar to firm up the float strips masking the process of "mortar filling" easier.
After the mortar has been filled in and cut off with a metal straight or feather edge, the float strips are removed and the voids filled.
Set forms for the top of the dam. Only the outside form can be screwed in place. The inside form must be braced as the shower membrane might be punctured. Remember to level the forms and ensure they are square to the side-walls. Also, provide a slope between the front of the dam and inside edge. When the top of the dam slopes into the shower, water will not sit on top of the dam avoiding problems later in the life of the shower.
Since the depth of this dam top was excessive, the installer used reinforcing wire set in the middle of the mortar bed.
Fill in and trowel off the top of the dam. Ledgers can also be used to stack trim. This worked nicely on the job due to the complicated nature of the trim used.
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