Homeowners and builders increasingly favor shower spaces which can function without a curb or would not require any build up over existing floor areas resulting in a step up into the shower. One important reason for this trend is: easier and safer access to the shower for older and/ or physically disabled persons. While this trend offers great design and business opportunities it also presents technical challenges which cannot be overcome by many conventional shower installation methods or products. Main challenges are safe recessing of a sloped shower base into an existing structural floor for a flush transition and the extension of waterproofing from shower area into surrounding floor areas no longer protected by a curb keeping water inside the shower area. To address all challenges for tile professionals, wedi engineered Fundo Ligno, a sloped shower base ¾ inches thin at its perimeter and available in various sizes. Ligno can be field modified. The installation within a ¾” plywood structure requires no cutting into joists. Loadbearing plywood is simply reinstalled between floor joists and over 2 x 6 or 2 x 4 blocking then attached to the joists. This guarantees a full support and protection of the tiled surface. The wedi typical strong cement based, reinforced surface is pre-sloped, directly tileable with large or small format tile. Ligno interlocks with wedi Building Panel used as waterproof backer board on walls as well as on the surrounding floor. Optionally, wedi‘s Subliner Dry Sheet Waterproofing membrane can be used. Both options offer a complete and professional system installation.
Step 1aCut 3/4” Plywood base out fitting the space of wedi Fundo Ligno. Safely install blocking along floor joists appr. 3/4” below top of floor joists. Adjust for thinset thickness under wedi Fundo Ligno base and / or the flooring underlayment installation adjacent to shower area to create a flush transition for waterproofing and tile between floor and shower area. Re-install 3/4” plywood over ...
Step 1b... blocking to have the plywood flush with the floor joists and fill with furring strips on top of floor joists in case the blocking / joist that carry the plywood under wedi base is installed higher than 3/4” deep from top of floor joists. Make sure the entire perimeter of the wedi Fundo Ligno base is supported by floor joists or adequate blocking. Make sure the plywood base shows no seams ...
Step 1c... where close to the cut out for the wedi Fundo Ligno drain. The cutout around the center of the 2” floor pipe must be 6 1/2” in diameter to allow drain recess and must not create any subfloor deflection. The pipe is cut square and even at 5/8” below the recessed subfloor top surface.
Step 2Assemble the drain unit following the instruction drawing.
Step 3Set up a continuous 1/4” bead of wedi Joint Sealant along the top side of the wedi Fundos’ valve groove profile.
Step 4Drop the drain body firmly into the sealant.
Step 5Turn the Fundo base upside down and apply the rubber and the fiber gasket.
Step 6Tighten the gaskets firmly to the bases' steel ring using the locking nut. Make sure the drain body is still safely received in the valve-bead of sealant.
Step 7Skim coat the thinset ANSI 118.4 and comb through with a 1/4” x 1/4” notched trowel channels pointing to the entrance.
Step 8Trowel the thinset on the rear side of the Fundo again using a 1/4” × 1/4” notched trowel. There are different ways to ensure good bond of the wedi base to the subfloor. Required is a setting bed thickness of min. 3/16" and max. of 5/16" (compressed). Applying thinset on both, ...
Step 9... wedi base and subfloor, is a best practice recommended to achieve full surface coverage adhesion. Press the wedi Fundo Ligno firmly into the thinset bed, ensuring that the installation is level and void free. Apply some weight equally and for at least 30 minutes (thinset bags).
Step 10Set up the rubber caulking gasket (with the bevelled side up) around the 2” pipe in the subfloor. The rubber gasket must be flush with the upper end of the 2” ABS or PVC pipe. Do Not use any Lubricants.
Step 11Tighten (squeeze) the rubber caulking gasket firmly with the caulking nut (use a flat headed screwdriver) and finally insert the plastic frame and strainer on top (without adhesive). The frame and drain cover will be held in a grout joint only once tiling commences.
Step 12Set up a continuous 1/2” bead of wedi Joint Sealant along the pans channel on the outer perimeter and only in areas where you can immediately install a building panel into the fresh sealant.
Step 13Push the wedi panel all the way into the channel of the shower base channel and its bead of sealant. Smooth out any pushed out sealant on inside seam using a putty knife. Fasten the panels directly to the studs starting 1 ft above the base and at a rate of 1 fastener per 1ft. One extra fastener is set into the seam to the next panel to crate a flush transition.
Step 14Apply continuous 1/2” beads of sealant between all connections of panels and install with thigthly butted seams. Excess sealant must be spread flat with a putty knife.
Step 15All seams and fastener heads in the assembly are covered with a secondary 1/2” bead of sealant and spread flat. The seams should be covered 1” on either side of seam. All fastener / washers are covered with sealant stretching 1” over the washer edges.
Step 16wedi Niches are installed in a cut out in the wedi wall and attached with it's flange right into the center of 16 o.c. studs. wedi Joint Sealant is set along the connection of wall to niche.
Step 172 Fasteners each side of the niche are set to create a flush transition to the wall panels. Another 1/2” bead of wedi Joint Seal ant is spread over fasteners and seams.
Step 18Apply thinset mortar over wood subfloor and reaching 4” into the wedi Fundo Ligno shower base. Fill the wedi Fundo Ligno channel with thinset or a strip of sealed on wedi Building Panel and apply thinset mortar to the lower corner of the wedi wall panels left and right of any entrance using 1/4” x 1/4” notch trowel.
Step 19aApply a modified thinset (ANSI 118.4 or equivalent) across the wood or cement board floor surface and now apply wedi Subliner Dry Sheet waterproofing membrane overlapping into the Ligno base for 4 inches. Apply wedi's prefabricated outside or inside sealing tape corners and sealing tape or Subliner Dry folds as a flashing to the wedi wall panels/Ligno and Subliner dry sheets as applicable.
Step 19bInstall this waterproofing system over the floor substrate outside the shower. All areas subject to water splashes and spray must be waterproofed. wedi recommends to waterproof the entire bathroom floor (including a flashing up into the wall at least to the height of a regular base board or 2" high) in spaces where curbless showers are being installed.
Step 19cAll seams and ends of the Subliner Dry sheets are covered with a 1/2” bead of wedi Joint Sealant and spread flat using a putty knife. Your shower is ready for tile once the thinset mortar has hardened! Alternatively to Subliner Dry sheet membrane system wedi building panels in 1/4” or 1/2” thickness can be used as the floor tile underlayment in lieu of cement board and Subliner waterproofing. wedi Building Panel would be installed over plywood subfloor and overlap and seal into the Ligno channel. In such application the Ligno base must be raised to allow its channel to fully stick out from the recessed area so wedi floor building panels can be interlocked with its channel. All seams to wedi walls or Ligno base are sealed internally with wedi Joint Sealant, and are covered with an external 1/2” bead of wedi Joint Sealant spread flat. Your shower is ready for tiling once thinset under wedi Subliner Dry or wedi Building Panels on floor has cured.