Installation Guide

20 INSTALLATION
Tiles
Once the tile installation is complete, retest
the heating cable and record values in the
heating cable tests log (page 30).
Allow the assembly to cure for 7 days after
grouting before putting the floor warming
into service.
4
Note: While the heating cable is protected by the DITRA-HEAT and DITRA-HEAT-TB matting, be careful when applying the mortar to not
damage the cable with the notched trowel.
Tile can be installed over DITRA-HEAT and
DITRA-HEAT-TB immediately; no need to
wait for the mortar to cure. Fill the matting
with unmodified thin-set mortar and comb
additional mortar over the matting using
a trowel that is appropriate for the size of
the tile.
1
Solidly embed the tiles in the setting material,
making sure to observe the open time of the
bonding mortar. If the mortar skins over prior
to tile installation, remove and reapply.
2
Periodically remove and check a tile to
ensure that full coverage is being attained.
3
Note: Coverage may vary with mortar consistency, angle at which the trowel is held, substrate flatness, etc. If full coverage is not achieved, remove
and reapply, making sure to verify proper mortar consistency and application. For large-format tiles, e.g., 12" x 12" (305 mm x 305 mm) and larger,
back-buttering the tiles with a skim coat of thin-set mortar is a useful way to help ensure proper coverage. The skim coat can fill in the concave area on
the back of the tile (ceramic tiles are not perfectly flat) and improve contact with the mortar combed on the substrate.
ESTIMATED THIN-SET COVERAGE
To bond DITRA-HEAT to the substrate:
Use one 50 lb. (22.68 kg) bag of mortar per 100 ft
2
(9.3 m
2
).
To bond the tile to the DITRA-HEAT, using a 1/4" x 3/8" (6 mm x 10 mm) square- or U-notched trowel:
Use one 50 lb (22.68 kg) bag of mortar per 40 - 50 ft
2
(3.7 - 4.6 m
2
).
To bond the tile to the DITRA-HEAT, using a 1/2" x 1/2" (13 mm x 13 mm) square- or U-notched trowel:
Use one 50 lb (22.68 kg) bag of mortar per 30 - 40 ft
2
(2.8 - 3.7 m
2
).
Operating Tips
• Do not place furniture or mats over the floor temperature sensor. They can act as insulation and raise the floor temperature reading at the thermostat.
This may cause the heating to turn off before the remainder of the floor reaches the desired temperature.
• Area rugs are not recommended over the DITRA-HEAT system.
• Futons, mattresses, floor-level furniture, pillows, etc. must not be placed directly onto the heated floor. Placement of items directly onto the heated floor
will prevent heat diffusion (i.e., air circulation) and could result in damage.