To rough-in the smaller shower, the crew installed 2-by vertical blocking to the web of the outer-bay joists to support horizontal blocks between the joist flanges. The center bay was left open for the drain stub.
In the large shower, part of an I-joist was cut out to accommodate the new drain, and a new joist was fished in next to it.
Fin Pan technical reps recommended cutting The TI-ProBoard with a wet saw to limit the number of glass fibers released in the air.
TI-ProBoards have interlocking edges that slide together. The strength of the panels comes from their ribbed profile, which interlocks with the mud base.
The crew cut the panels to length, trimmed the last panel to width, then slid the assembled pan base under the drain flange and fastened it to the joists.
Panels are fastened to the framing with proprietary screws, which are corrosion-resistant and have large, pan heads.
Designed to add stiffness, Permat is not a waterproofing membrane. It was laid into a bed of thinset, and then its open mesh was filled and floated with more thinset.
As the walls were installed, care was taken to make sure the drop-in tiled drain cap still had proper clearance.
An approved mesh was applied at the seams with thinset, then the walls were waterproofed with Laticrete 9235.
The drain cover is a stainless steel tray with fixed metal feet that stand in the drain channel. Raised edges on the tray contain the tile, which gets installed in thinset and grouted.
In preparation for the glass enclosure, a stainless steel U-channel was bedded in silicone and secured with stainless steel screws to receive the sidelight at the floor.