Installation Guide

WOOD — Floors, Interior - Ceramic or Porcelain Tile 5
19.2" (488 mm) o.c. joist spacing, single layer OSB
or plywood subfloor
DH-W19-T-16
Areas of Application
over any even and structurally sound OSB or
plywood subfloor with 19.2" (488 mm) o.c.
joist spacing
interior dry or wet areas
Limitations
minimum 2" x 2" (50 mm x 50 mm) tile
for natural stone, see detail DH-W-S (page 6)
and natural stone discussion (page 26)
Requirements
maximum spacing of joists, I-joists, or floor
trusses is 19.2" (488 mm) o.c.
minimum subfloor thickness – 23/32",
3/4" nom. (19 mm) tongue-and-groove with
1/8" (3 mm) gap between sheets.
Substrate Preparation
verify that subfloor panels are properly
fastened to framing members.
any leveling of the subfloor must be done
prior to installing DITRA-HEAT and DITRA-
HEAT-TB.
Movement Joints
DITRA-HEAT and DITRA-HEAT-TB do not
eliminate the need for movement joints,
including perimeter joints, within the tiled
surface. Movement joints must be installed in
accordance with industry standards and
norms; see page 11 of this Handbook, TCNA
EJ171, and TTMAC 301 MJ.
Setting and Grouting Materials
latex portland cement (p.c.) mortar –
ANSI A118.11
unmodified thin-set mortar – ANSI A118.1
grout – ANSI A118.3, A118.6, A118.7, A118.8
Setting and Grouting Specifications
tile – ANSI A108.5
grout – ANSI A108.6, A108.9, A108.10
Other Considerations
tightly butted and/or tented plywood or OSB
seams must be addressed prior to installing
DITRA-HEAT and DITRA-HEAT-TB.
vapor barrier on crawl space floors according
to regional building codes.
where a waterproof floor is required, all
DITRA-HEAT and DITRA-HEAT-TB seams
and floor/wall transitions must be sealed with
KERDI-BAND using unmodified thin-set
mortar; see page 10.
DH-W24-T-16
24" (610 mm) o.c. joist spacing, double layer OSB
or plywood subfloor
Areas of Application
over any even and structurally sound double
layer OSB or plywood floor
interior dry or wet areas
Limitations
minimum 2" x 2" (50 mm x 50 mm) tile
Requirements
maximum spacing of joists, I-joists, or floor
trusses is 24" (610 mm) o.c.
double layer wood floor consisting of:
• minimum subfloor thickness – 23/32",
3/4" nom. (19 mm) tongue-and-groove
• minimum underlayment thickness –
11/32", 3/8" nom. (10 mm)
Substrate preparation
verify that subfloor panels are properly
fastened to framing members.
underlayment – minimum 11/32", 3/8" nom.
(10 mm)-thick Exposure 1, plugged-face
plywood or OSB with 1/8" (3 mm) gap
between sheets; see page 14 for
underlayment installation guidelines.
any leveling of the subfloor must be done
prior to installing DITRA-HEAT and DITRA-
HEAT-TB.
Movement Joints
DITRA-HEAT and DITRA-HEAT-TB do not
eliminate the need for movement joints,
including perimeter joints, within the tiled
surface. Movement joints must be installed in
accordance with industry standards and
norms; see page 11 of this Handbook, TCNA
EJ171, and TTMAC 301 MJ.
Setting and Grouting Materials
latex portland cement (p.c.) mortar –
ANSI A118.11
unmodified thin-set mortar – ANSI A118.1
grout – ANSI A118.3, A118.6, A118.7, A118.8
Setting and Grouting Specifications
tile – ANSI A108.5
grout – ANSI A108.6, A108.9, A108.10
Other Considerations
tightly butted and/or tented plywood or OSB
seams must be addressed prior to installing
DITRA-HEAT and DITRA-HEAT-TB.
vapor barrier on crawl space floors according
to regional building codes.
where a waterproof floor is required, all
DITRA-HEAT and DITRA-HEAT-TB seams
and floor/wall transitions must be sealed with
KERDI-BAND using unmodified thin-set
mortar; see page 10.
Ceramic or porcelain tile
Unmodified thin-set mortar
DITRA-HEAT
or DITRA-HEAT-TB
uncoupling membrane
and heating cables
Latex p.c. mortar
Double layer of plywood
or OSB
I-joists or
trusses
Ceramic or porcelain tile
Unmodified thin-set mortar
DITRA-HEAT
or DITRA-HEAT-TB
uncoupling membrane
and heating cables
Latex p.c. mortar
Single layer of plywood
or OSB
Joists, I-joists, or
trusses