Schluter®-DITRA Installation Handbook 2020 The Universal Underlayment for Ceramic and Stone Tile
Schluter®-DITRA Specifically designed as an underlayment for ceramic and stone tile Ceramic and stone tiles are durable, easy to maintain, and hygienic, representing the ideal surface coverings. However, today’s lightweight construction methods can make the installation of hard surface coverings particularly challenging. In order to protect the integrity of the tile assembly, an underlayment that performs multiple functions is required.
CONTENTS WOOD 4 Floors, Interior - 16, 19.2, & 24-inch o.c.
WOOD Every substrate presents unique challenges All wood materials, including OSB, plywood, and framing members, are subject to expansion, contraction, bending, and deflection as a result of changes in moisture content and loading. Further, these deformations fluctuate over the life of the building structure.
19.2" (488 mm) o.c. joist spacing, single layer OSB or plywood subfloor D-W19-T-20 Ceramic or porcelain tile Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar DITRA or DITRA-XL uncoupling membrane Schluter ALL-SET®, Schluter FAST-SET®, or modified thin-set mortar Single layer of plywood or OSB Areas of Application over any even and structurally sound OSB or plywood subfloor with 19.2" (488 mm) o.c.
D-W24-XL-T-20 Ceramic or porcelain tile Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar DITRA-XL uncoupling membrane Schluter ALL-SET®, Schluter FAST-SET®, or modified thin-set mortar Single layer of plywood or OSB 24" (610 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 24" (610 mm) o.c.
Floors, Interior - Existing Vinyl Floors D-V-T-20 Areas of Application over any even and structurally sound substrate with existing vinyl flooring interior dry or wet areas Tile or wood base Ceramic, porcelain or stone tile RONDEC Limitations minimum 2" x 2" (50 mm x 50 mm) tile cushioned vinyl unacceptable perimeter bonded vinyl flooring unacceptable multiple layers of vinyl unacceptable DILEX-EKE Schluter SET , Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar ® Requirements for w
CONCRETE Every substrate presents unique challenges There are various challenges associated with the installation of hard surface coverings on concrete substrates. To begin, the coefficient of thermal expansion of concrete is close to twice that of ceramic tile. Additionally, tile contractors are often expected to install tile over young concrete (concrete cured less than 28 days).
GYPSUM Every substrate presents unique challenges Bonding ceramic or stone tiles directly to gypsum concrete substrates is generally considered questionable or not recommended. The challenges associated with gypsum-based underlayments include the requirement of an extended drying period before installing tile and continued sensitivity to the reintroduction of moisture throughout the life of the installation.
HEATED FLOORS Every substrate presents unique challenges Radiant heating is one of the fastest growing market segments in the construction industry. Unlike other surface coverings, the low thermal resistivity of ceramic and stone tiles allows them to be used in radiant heat applications without sacrificing the energy efficiency of the system. However, there are inherent challenges in combining rigid surface coverings with radiant panel heating systems.
Wood Substrate D-RHTS-20 Thin slab (lightweight or gypsum concrete) Ceramic, porcelain or stone tile Areas of Application over lightweight or gypsum concrete thin slab placed over structurally sound wood or concrete subfloor interior dry or wet areas Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar DITRA or DITRA-XL uncoupling membrane Limitations minimum 2" x 2" (50 mm x 50 mm) tile Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar
ACCESS FLOOR PANELS D-AFP-T-20 Floors, Interior - Ceramic or Porcelain Tile Ceramic or porcelain tile Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar DITRA or DITRA-XL uncoupling membrane Schluter ALL-SET®, Schluter FAST-SET®, or modified thin-set mortar Primer Access panels 24" x 24" Access flooring pedestals Raised access flooring, 24" x 24" panels Areas of Application over any even and structurally sound 24" x 24" (600 x 600 mm) panels with corners supported on pede
WATERPROOFING Every substrate presents unique challenges 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, showers, and barrier free showers.
MOVEMENT JOINTS Every substrate presents unique challenges DISCUSSION Movement joints are an integral part of any tile assembly. The various components of a tile assembly (tile, mortar, substrate, etc.) have unique physical characteristics that affect their behavior. Specifically, these components will expand and contract at different rates, according to each component’s intrinsic physical properties, with changes in moisture, temperature, and loading (both dead and live loads).
1 Schluter®-DILEX-EKE Typical movement joint applications Perimeter Joints Perimeter joints are provided at the outer edges of any tile installation to accommodate movements attributable to changes in moisture, temperature, and loading. See figures 1, 2, and 3.
Note regarding residential applications Due to the increased popularity of continuous tile installations (i.e., tile continuing from room to room on a given floor), movement joints have become both increasingly important and increasingly difficult to provide. For instance, consider the residential installation shown in Figure 5.
WOOD UNDERLAYMENT Plywood/OSB underlayment installation guidelines DISCUSSION In some applications referenced in this Handbook, adding a layer of plywood or OSB before installing Schluter®-DITRA and the ceramic or stone tile covering is required to reduce deflection and curvature of the sheathing between the joists.
INSTALLATION Schluter ®-DITRA and Schluter ®-DITRA-XL Preparation • The substrate must be clean, even, and load bearing. Any leveling of the subfloor must be done prior to installing DITRA and DITRA-XL. • For wood substrates, verify that panels are properly fastened. Tightly butted and/or tented plywood or OSB seams must be addressed prior to installing DITRA and DITRA-XL. If a plywood/OSB underlayment is to be installed, follow the Wood Underlayment guidelines on page 17.
Waterproofing The following steps are required for waterproofing only: 1 At the joints, fill the cut-back cavities with Schluter SET®, Schluter ALL-SET®, Schluter FAST-SET®, or unmodified thin-set mortar, approximately 8" (203 mm) wide, centered over the joint.
THIN-SET FACTS Discussion of thin-set mortars and Schluter®-DITRA installations Schluter®-Systems offers thin-set mortars designed for use with Schluter® membranes and boards. All Schluter®-Systems’ thin-set mortars, including the Schluter ALL-SET® and Schluter FAST-SET® modified varieties, can be used to set tile over Schluter®-DITRA, DITRA-HEAT, KERDI, KERDI-BOARD non absorptive substrates.
THIN-SET DISCUSSION Evaluation of mortar types used with Schluter®-DITRA As stated previously in this Handbook, Schluter®-Systems recommends the use of unmodified thin-set mortar between DITRA and the ceramic or porcelain tile covering. In this section, we will address concerns regarding the use of unmodified mortar over DITRA and provide insight into the overall function of the tile assembly using experimental data.
TESTING & CERTIFICATIONS Product Evaluation Schluter®-Systems is committed to providing reliable installation systems for ceramic and stone tile. As part of this commitment, we have invested considerable resources in testing our products and obtaining certifications where applicable to provide our customers and local code officials with relevant data that supports the efficacy of our systems. All the testing referenced below was performed by independent laboratories.
HOW DOES IT WORK? Explanation of how Schluter®-DITRA functions To understand how the DITRA system works, it is important to first understand what a tile assembly is, how it functions, and how stresses occur within the assembly. A tile installation is a composite assembly that consists of layered components (underlayments, bonding mortars, tile, etc.).
NATURAL STONE Discussion of natural stone and single-layer wood subfloors Natural stone is a product of nature with a wide variety of colors, patterns, and textures that come together to distinguish it as one of the premiere surface coverings available on the market. Some of stone’s characteristics, which add to its beauty and uniqueness, are veins, fissures, starts, and dry-seams.
Q. What distinguishes DITRA-XL from DITRA? A. Since the uncoupling function of DITRA is founded on its geometric flexibility to provide a forgiving shear plane, increasing the height of the product produces additional protection against stresses being transferred between the tile and supporting substrate. Testing reveals that this increase is significant.
SOUND CONTROL Discussion of sound control in conjunction with ceramic & stone tile Controlling sound transmission through floor/ceiling assemblies in multi-story construction can present challenges to architects and design professionals, particularly when hard surface coverings, including ceramic and stone tiles, are used. This is because sound control materials tend to be compressible and may not provide adequate support for the tile layer in thin-set applications.
PRODUCT SELECTION Choosing between Schluter®-DITRA and DITRA-XL How Do I Choose Between DITRA and DITRA-XL? Schluter uncoupling membranes provide the four essential functions for successful tile installation over a wide range of substrates, including plywood/OSB, concrete, gypsum, heated floors, etc. The choice between using DITRA or DITRA-XL depends on the nature of the particular project or application. The following points will help differentiate between the two products.
Notes : 28 NOTES
Notes : NOTES 29
WARRANTIES Schluter ®-DITRA & Schluter ®-DITRA-XL Uncoupling Membrane 10-Year Limited Warranty LIMITED WARRANTY COVERAGE: Subject to the conditions and limitations as stated in this Schluter®-DITRA and Schluter-DITRA-XL Uncoupling Membrane 10-Year Limited Warranty (the “Limited Warranty”), Schluter Systems warrants that its Schluter®-DITRA and Schluter-DITRA-XL uncoupling membranes (the “Products”) will be free from manufacturing defects and will perform as described in the Schluter®-DITRA Installation Hand
Schluter®-Systems Lifetime Thin-Set System Extended Limited Warranty LIMITED WARRANTY COVERAGE: Subject to the conditions and limitations as stated in this Lifetime Thin-Set System Extended Limited Warranty (the “Limited Warranty”), Schluter Systems warrants that a Thin-Set System (defined hereafter) will be free from manufacturing defects and will perform as described in the applicable installation handbook(s) and/or technical data sheet(s) (collectively, the “Written Materials1” ) for the lifetime (define
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