Floors, Interior - Ceramic or Porcelain Tile

16" (406 mm) o.c. joist spacing, single layer OSB or plywood subfloor

Areas of Application

  • over any even and structurally sound OSB or plywood subfloor with 16" (406 mm) o.c. joist spacing
  • interior dry or wet areas


  • minimum 2" x 2" (50 mm x 50 mm) tile
  • not intended for natural stone; see detail D-W-S, page 6


  • maximum spacing of joists, I-joists, or floor trusses is 16" (406 mm) o.c.
  • minimum subfloor thickness - 19/32", 5/8" nom. (16 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 Schluter-DITRA

Movement Joints

  • Schluter-DITRA does not eliminate the need for movement joints, including perimeter joints, within the tiled surface. Movement joints should be installed in accordance with industry standards and norms; see page 20 of this Handbook, TCA 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 Schluter-DITRA
  • vapor barrier on crawl space floors according to regional building codes where a waterproof floor is required, all Schluter-DITRA seams and floor/wall transitions must be sealed with Schluter-KERDI-BAND using unmodified thin-set mortar; see page 14

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