DITRA-Heat in Shower | Detail & Tray Adjustments
DH-SH-23 is the detail taken from the DITRA-Heat installation handbook with critical information for installing DITRA-Heat in a shower application. Photos of the detail are included below.
When Using Schluter Shower Trays
Remove the center break-out section of the tray that supports the drain flange, highlighted in green below.
Use the break-out as a template to cut a ring out of the DITRA-Heat membrane that you are using. Install the DITRA-Heat membrane underneath the break-out support to lift the flange assembly up to meet the DITRA-Heat membrane that will be installed over the shower tray as shown below.
KERDI waterproofing membrane must be installed over the wire in the shower floor so that the sealed waterproof envelope is over the whole assembly.
For KERDI-Line drains, use the grey foam channel body support as the template to cut the DITRA-Heat membrane.
When using deck mud/dry pack mortar to float the shower floor.
Do not float flush to the edge of the drain flange. Flange should be 1/4” or 5/16” higher than the rest of the floor float. This will allow the DITRA-Heat membrane to flush out with the height of the drain flange.
KERDI waterproofing membrane must be installed over the wire in the shower floor so that the sealed waterproof envelope is over the whole assembly.
PHOTOS of THE ABOVE
It is recommended to use two wires in a shower area. One for the main floor and one for the shower floor. As long as they are both under a combined 15 amps they may be plugged into the same thermostat. The cold splice and endsplice of the shower wire should always be on the main floor so that it is not underneath the KERDI waterproofing. That way - if it needs to be repaired at a splice - it can be. DO NOT RUN WIRES UNDER CURBS OR FIXED OBJECTS. See picture below to illustrate how to route a wire over a curb and back out onto main floor.
REMEMBER
Read installation handbook and adhere to the instructions. Photo document your installation. TCNA requires 95% or better coverage in wet areas. DO NOT SPOT SET TILE. Installation handbook with have all answers and much greater detail ensuring success of your installation.
• Ensure correct thin-set mortar (we highly recommend use of Schluter modified ALL-Set mortars for prep work and tile install).
• Use correct trowel size.
• Burn mortar into substrate with flat side of trowel. Notch mortar with direction troweling; do not swirl trowel.
• Back butter tile.
• Massage tile into directional troweled ridges in perpendicular movements to knock the ridges down folding them into each other while allowing air to escape.
• DO NOT CLEAN JOINTS WITH SHARP OBJECTS. No knife, no screw driver, no oscillating tool. Use a sponge or toothbrush and clean joints as you go.
• Consider using a separate wire for the shower vs the rest of the floor. Wires in wet areas cannot be repaired. Wire may be able to plug into the same thermostat if the combined amperage between the floor wire and the shower wire is less than 15 amps.
• DO NOT run the heat wire underneath shower curbs or walls.
• DO NOT install the cold splice or the end splice under the KERDI membrane in the shower area. Plan to have them under the tile assembly on the main floor area.
• Avoid bending the heat wire at sharp angles.
• DO NOT remove the silver tag from the wire. Replace with one of the two extras if the cold lead is cut short. Recommended to place the second extra in the panel next to the breaker dedicated to the heat system.
