Installation Guide

10 WATERPROOFING — Floors, Interior
Every substrate presents unique challenges
WATERPROOFING
Floors, Interior - Ceramic or Stone Tile
DH-WP-14
Areas of Application
over any even and structurally sound
substrate where waterproofing is desired
Limitations
minimum 2" x 2" (50 mm x 50 mm) tile
Requirements
all seams in DITRA-HEAT matting and floor/
wall transitions must be sealed with
KERDI-BAND using unmodified thin-set
mortar. Note: KERDI-BAND must lap
DITRA-HEAT at seams and at floor/wall
transitions by a minimum of 2" (50 mm) in
order to maintain waterproof integrity
Other Considerations
seaming DITRA-HEAT, including floor/wall
connections, with KERDI-BAND may be
appropriate in cases where a break in the water
line of an ice maker or dishwasher can damage
pre-existing moisture-sensitive substrates and
underlayments. KERDI-BAND floor/wall
connections are just as easily concealed with
wood base as with tile. KERDI-BAND floor/wall
connections in dishwasher alcoves are parged
with thin-set mortar.
in some applications the vertical section of
the floor/wall transition will not accept a bond
to unmodified thin-set mortar. Connections
to such elements can be achieved using
KERDI-FIX or suitable trowel-applied
waterproofing materials, such as those that
require atmospheric moisture to cure (e.g.,
urethane sealant).
KERDI-DRAIN or KERDI-LINE may be used
to provide drainage in DITRA-HEAT
applications. DITRA-HEAT is sealed to the
fleece-laminated KERDI-DRAIN bonding
flange with a section of KERDI membrane
using unmodified thin-set mortar. KERDI-FIX
is used to seal the section of KERDI to the
stainless steel KERDI-DRAIN bonding flange.
DITRA-HEAT is sealed to the KERDI
waterproofing collar on KERDI-LINE using
unmodified thin-set mortar.
Today’s construction methods, which include the use of lightweight, moisture-sensitive materials, such as plywood, OSB, and gypsum
concrete, have made the installation of hard surface coverings particularly challenging. If wood or gypsum concrete substrates are exposed
to moisture, the tile layer above can be damaged as a result.
Typical areas that require waterproofing include tub surrounds and showers. However, there are other commonly tiled areas that may,
through unexpected circumstances, become exposed to significant amounts of water; for example, an overflowed toilet, or ruptured
dishwasher, icemaker, or washing machine lines, which can result in flooding.
Waterproofing these floors can save an owner from replacing the tile assembly and substructure in the event of a leak.
DITRA-HEAT installations can be made waterproof with minimal effort. Since the matting is made of waterproof polypropylene, the only
extra step necessary is to seal the seams and floor/wall connections. This is easily accomplished by applying KERDI-BAND to these areas
using an unmodified thin-set mortar. The result is a waterproof installation that will not suffer damage in the event of an unexpected water
leak. KERDI-DRAIN or KERDI-LINE may be used to provide drainage in DITRA-HEAT installations.
Tile or wood base
Ceramic or stone tile
RONDEC
DILEX-EKE
Unmodified thin-set mortar
KERDI-BAND
DITRA-HEAT
uncoupling membrane
and heating cables
Thin-set mortar
per appropriate
detail