weber.xerm 843

Colour:
white

Bed thickness:
up to 6 mm

Water demand:
approx. 6.3 liters / 18 kg

Storage:
The product can be stored for at least 9 months in its original unopened packaging if kept dry and protected from moisture.

Fields of application

weber.xerm 843 is used for bonding the impact sound insulation and de-coupling boards weber.sys 832 on wooden floors, concrete, and screeds, as well as for fixing ceramic tiles on the pre-said boards. Also for fixing floor and wall ceramic tiles, mosaic, stoneware brick slips, porcelain stoneware, earthenware, split tiles and rigid foam boards on concrete, lightweight concrete, aerated concrete, cement and cement-lime plasters, cement screeds and calcium-sulphate screeds (heated and non-heated), lightweight multi-use tilebackers weber.sys 834 and gypsum paperboards, using the thin-bed method.
Suitable on young cement screeds between the 3rd and the 7th day following their application.
Furthermore, for use on critical substrates, like asphalt boards, old tiles, chipboards and timber planks in combination with the boards weber.sys 832.
For use indoors.

Main features

• EMICODE EC 1PLUS: very low emission of volatile substances
• C2 TE / S2: C2: pull-off strength ≥ 1.0 N/mm2 in all storage conditions – T: thixotropic, slip ≤ 0.5 mm – E: extended open time ≥ 30 minutes – S2: deformation ≥ 5 mm
• quick-setting: quickly open to pedestrian traffic and for grouting works
• high deformability
• high bonding strength
• high yield
• convenient for critical substrates
• can be directly applied on young screeds (between 3rd and the 7th day)
• suitable for heated floor constructions
• for walls and floors

General notes

• Limits of use: do not use weber.xerm 843 outdoors and in areas permanently underwater; in these cases use the epoxy resin adhesive weber.xerm 847.
• For full information relating to allowed substrates and tile coverings, refer to the Weber chart “Overview Tile Adhesives”.
• All characteristics mentioned in this data sheet are based on a temperature of +23 °C without draught and a relative humidity rate of 50%.
• Higher temperatures and lower humidity rates accelerate, lower temperatures and higher humidity rates delay the setting process.
• Comply with the national standards and/or guidelines, for ex. DIN 18157 “Execution of tilings and coverings” and the leaflets of ZDB (Central Association of German Construction Industry); if not issued and if necessary, request technical advice.
• Take preliminary measures before fixing coverings on wooden (timber planks) or metal substrates, for ex. with de-coupling boards combined with a self-levelling mortar or an epoxy resin covered with silica sand on top. Request technical advice.
• Respect the maximum residual moisture content of the substrate at the time of installation of ceramic coverings and natural stones; it should not exceed 2.0% CM-% (by weight) in case of heated or non-heated cement screeds, 0.5% CM-% (by weight) in case of heated or nonheated anhydrite screeds, 1.0% CM-% (by weight) in case of gypsum plasters, and air-dry for cement and cement-lime renders/plasters. The moisture content must be measured with a carbide hygrometer (CM) as a rule.
• For installation of natural or artificial stone slabs, follow the supplier’s recommendations. If in doubt, carry out preliminary tests.
• Do not install tiles, slabs or natural stones that have been stored damp, wet, or too cold.
• Do not use a material that has already stiffened.

Special notes

• When levelling substrates with low compressive strength and bulk density (e.g. gypsum plasters, lightweight plasters, aerated concrete, etc.), calcium sulphate screeds or mastic asphalt screeds, apply the tile adhesive in a maximum thickness of 3 mm.
• Do not use in contact with non-ferrous metals, such as aluminum, copper, lead or zinc. Used stainless steel components, e.g. rails and edge protector angles.