Schluter®-DITRA Installation Handbook 2015 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 6 Floors, Interior - 16, 19.2, & 24-inch o.c.
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.
Even Transitions to Hardwood Flooring In many thin-set ceramic tile applications, one of the goals is to minimize the thickness of the assembly to reduce height transitions from the tile to other floor coverings such as carpet, engineered wood, or vinyl. At 1/8" (3 mm)-thick, DITRA accomplishes this goal while providing the four essential functions for successful tile installations. Schluter floor profiles finish and protect tile edges at these transitions to complete the installation.
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-15 Ceramic or porcelain tile 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 Unmodified thin-set mortar DITRA or DITRA-XL uncoupling membrane Latex p.c.
24" (610 mm) o.c. joist spacing, single layer OSB or plywood subfloor D-W24-XL-T-15 Ceramic or porcelain tile Unmodified thin-set mortar Areas of Application over any even and structurally sound OSB or plywood subfloor with 24" (610 mm) o.c. joist spacing interior dry or wet areas DITRA-XL uncoupling membrane Latex p.c.
Floors, Interior - Existing Vinyl Floors D-V-T-15 Areas of Application over any even and structurally sound substrate with existing vinyl flooring interior dry or wet areas Tile or wood base Ceramic or stone tile Limitations minimum 2" x 2" (50 mm x 50 mm) tile cushioned vinyl unacceptable perimeter bonded vinyl flooring unacceptable multiple layers of vinyl unacceptable RONDEC DILEX-EKE Unmodified thin-set mortar KERDI-BAND Requirements for wood substrates, subfloor/underlayment configuration accordin
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-15 Thin slab (lightweight or gypsum concrete) Ceramic 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 Unmodified thin-set mortar DITRA or DITRA-XL uncoupling membrane Limitations minimum 2" x 2" (50 mm x 50 mm) tile Unmodified thin-set mortar Requirements for wood substrates, subfloor/underlayment configuration according to detail D-W16-T, D-W19-T, D-W24-T, or D-W2
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 and showers.
EXTERIOR APPLICATIONS Every substrate presents unique challenges Ceramic and stone tiles are ideal surface coverings for the exterior and have been used successfully for thousands of years. Exterior balconies and terraces are ideal opportunities for the installation of tiled surfaces. However, these installations have typically presented significant challenges to tile setters.
D-EXT-OS-15 Concrete or Wood Substrate Balcony and Terrace 1. Concrete or wood structure For wood substrates, subfloor/underlayment configuration according to detail D-W16-T, D-W19-T, D-W24-T, or D-W24-XL-T; D-W24-XL-T for use with Schluter®-DITRA-XL only. 11 2. Roofing membrane The roofing membrane must be sufficiently sloped (1.5 - 2%) and is necessary for the proper function of the assembly. 9 10 3. Schluter®-TROBA-PLUS Drainage mat for sustained water drainage. 4.
Schluter ®-TROBA/-TROBA-PLUS TROBA and TROBA-PLUS are reliable, long-lasting drainage mats for installation over horizontal, sloped waterproofing layers. Any water that penetrates the mortar bed is directed under normal gravitational force to the drainage exits. In addition, the waterproofing layer is effectively protected from damage. A B Schluter ®-BARA-RTK BARA-RTK is an edging profile with a drip lip for installation over an existing sloped substrate.
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).
Typical movement joint applications 1 Schluter®-DILEX-EKE 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 Easy Step-by-Step Installation A step-by-step installation video is available. E-mail us at info@schluter.com or call us at 1-800-472-4588 (USA) or 1-800-667-8746 (Canada). To see a video clip, go to www.schluter.com.
THIN-SET FACTS Discussion of thin-set mortars and Schluter®-DITRA installations QUESTION Can ceramic tile, including porcelain tile, be set on DITRA with unmodified thin-set mortar? ANSWER YES. In fact, we recommend it. Here’s why: Portland cement-based unmodified thin-set mortars are dependent on the presence of moisture for hydration in order to gain strength. Since DITRA is impervious, it does not deprive the mortar of its moisture.
TESTING 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.
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.
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.).
PRODUCT & ORDERING INFO The ordering information for the Schluter®-DITRA, Schluter®-DITRA-XL and Schluter®-KERDI components outlined in this Handbook is located below. For technical support, Illustrated Price List, or to receive additional information on our complete product line, please call 1-800-472-4588 (USA) or 1-800-667-8746 (Canada), or visit our comprehensive website at www.schluter.com.
Schluter ®-KERDI-FLEX KERDI-FLEX is a flexible polyethylene waterproofing strip used to seal movement joints over DITRA in specialty applications where large movements are expected, i.e. over expansion joints or construction joints. Schluter ®-KERDI-FLEX Waterproofing strip for use above movement joints Item No.
Schluter ®-DITRA-ROLLER Used to embed DITRA membranes in the bond coat during membrane installation. The lightweight DITRA-ROLLER features a 14-1/2" (37 cm) wide roller and a shelf for placing 50 to 75 lbs of weight (e.g., bag of thin-set mortar or grout, box of tiles, etc.). Between uses, it can be conveniently disassembled for transport and storage. Schluter ®-DITRA-ROLLER Used to embed DITRA in the bond coat Item No.
WARRANTY Schluter ®-DITRA & Schluter ®-DITRA-XL 10-Year Limited Warranty COVERAGE AND CONDITIONS: Subject to the conditions and limitations as stated hereinafter, Schluter-Systems* warrants that Schluter®-DITRA or Schluter®-DITRA-XL (the “Products”) will meet all composition and performance criteria for a period of ten (10) years from the date of purchase only when the Products are used and installed in accordance with the terms and conditions of the Schluter®-DITRA Installation Handbook and industry standa
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