Application and Function
Schlüter-DITRA-HEAT is a polypropylene membrane with a cut-back stud structure and an anchoring fleece laminated on the underside. It is a universal substrate for tile coverings, which serves as an uncoupling, crack bridging, waterproofing, vapour pressure equalisation layer and is designed for the attachment of heating cables.
Schlüter-DITRA-HEAT-DUO features a 2 mm special anchoring fleece on the underside, which bonds with the adhesive, while also reducing impact sound and enabling a faster heat-up response. The substrate for the installation of DITRA-HEAT must be level and ready to bear weight. Schlüter-DITRA-HEAT is installed in thinbed adhesive suitable for the substrate with a notched trowel (recommended size: 6 x 6 mm). The anchoring fleece on the underside of DITRA-HEAT is then fully embedded in the adhesive to ensure a mechanical bond of the fabric in the adhesive. The curing window of the adhesive has to be taken into consideration. In floor areas, the heating cables can be installed immediately after adhering DITRA-HEAT matting with a minimum spacing of 9 cm (every third stud = 136 W/m²).
In the case of wall installation, the heating cables are installed once an adequate adhesive bond has been reached. Installers can choose between installation spacing of 6 cm (every second stud = 200 W/m²) and 9 cm (every third stud = 136 W/m²).
The use of mats is recommended for wall areas. The tile or stone covering is professionally installed directly over DITRA-HEAT membrane in accordance with the applicable standards. The bedding adhesive anchors with the cut-back stud structure of the DITRA-HEAT membrane.
Schlüter-DITRA-HEAT / -HEAT-DUO is waterproof and can withstand all chemical stresses that typically occur in conjunction with tile coverings. Where required, an approved bonded waterproofing assembly can be created with DITRA-HEAT / -HEAT-DUO in specific areas.
Use the cable tester Schlüter-DITRA-HEAT-E-CT to measure the resistance of the electrical heating cables DITRA-HEAT-E-HK and the remote sensors included with the thermostats DITRA-HEAT-E. The device monitors the resistance of the heating cables during the entire installation phase. An acoustic signal will sound to alert the installer in the event of damage. The DITRA-HEAT-E-CT switches off automatically approximately 1 hour after the last “keystroke”.
Summary of functions
a) Uncoupling
Schlüter-DITRA-HEAT uncouples the covering from the substrate and neutralise’s stresses between the substrate and the tile or stone covering that result from different deformation processes. The material effectively bridges tension cracks from the substrate and ensures that they are not transferred to the tile covering.
b) Waterproofing
Schlüter-DITRA-HEAT / -HEAT-DUO is a waterproof polypropylene membrane with a relatively high water vapour diffusion seal. When properly installed at the abutting joints as well as at wall transitions and connections to building components, DITRA-HEAT / -HEAT-DUO can form part of an approved bonded waterproofing assembly with the tile covering. Schlüter-DITRA-HEAT / -HEAT-DUO can be used in accordance with the German waterproofing standard DIN 18534. Water exposure classes: W0-I to W3-I*. Furthermore, DITRA-HEAT / -HEAT-DUO features the national technical approval (abP) required in Germany.
Moisture load class according to ZDB: 0 to B0 and A.
Schlüter-DITRA-HEAT / -HEAT-DUO features European Technical Approval (ETA) pursuant to ETAG 022 (watertight covering kits) and bears a CE mark. It must be ensured that only system-approved thin-set tile adhesives are used in areas that require CE conformity or compliance with the general certificate of national technical approval. Please contact the address specified in this data sheet for further information on suitable thin-set tile adhesives and the corresponding test certificates.
Schlüter-DITRA-HEAT / -HEAT-DUO therefore protects the substrate from damage that results from permeating moisture and aggressive substances.
* With abP and/or in compliance with ETA according to ETAG 022. Please contact our Application Technology department for further information regarding use and installation.
c) Load distribution (load induction)
Tiles that are installed in floor areas over DITRA-HEAT should at a minimum have a size of 5 x 5 cm and a thickness of 5.5 mm. The indentations of DITRA-HEAT with their tile adhesive filling transfer the traffic loads impacting the tile covering directly to the substrate. This makes tile coverings installed over DITRA-HEAT especially durable. If high traffic loads are expected (e.g. in commercial areas) or if the floor must accommodate large point loads (such as grand pianos, fork lifts, shelf systems), the selected tiles must feature the necessary thickness and pressure stability for the corresponding application area. In Germany, the guidelines of the information sheet “Ceramic floor coverings for high mechanical impact” must be observed for tile thicknesses.
Tiles must be fully embedded in the tile adhesive in areas with high traffic loads. Please note that the contact surface of DITRA-HEAT is approximately 50% of the entire area, which may cause a corresponding reduction in pressure resistance in the presence of high point loads. Schlüter-DITRA-HEAT-DUO features a special 2-mm anchoring fleece on the underside and can be used for traffic loads up to 3 kN/m². This includes residential and commercial premises with light foot traffic (residential buildings, office and administrative spaces, restaurants, hotels, conference rooms, nursing stations and patient rooms etc.)
As a rule, the impact of hard objects must be avoided on ceramic coverings for both DITRA-HEAT and DITRA-HEAT-DUO. Tiles should have minimum dimensions of 5 x 5 cm.
d) Bonded assembly
Due to the bond of the fleece fabric with the thin-bed adhesive over the substrate and the mechanical anchoring of the thin-set adhesive in the cut-back stud structure, DITRA-HEAT creates a lasting bond of the tile covering with the substrate. Schlüter-DITRA-HEAT can therefore be used in wall and floor areas.
e) Thermal separation
Schlüter-DITRA-HEAT-DUO features a 2 mm special anchoring fleece on the underside, which bonds with the tile adhesive, while also reducing impact sound and enabling a faster heat-up response.
f) Sound insulation
An impact sound insulation improvement (ΔLW) of 13 dB was measured in a full installation of DITRA-HEAT-DUO (in accordance with DIN EN ISO 10140). However, the actual impact sound reduction of an assembly depends on local circumstances (construction system) and may differ from this value. Consequently, the determined test values cannot be applied generally to all construction site situations.