ARDEX W 820 Super Finish

ARDEX W820 Super Finish - Plastering and Finishing Putty for walls and ceilings

Polymer-modified putty for manual or pump application. Suitable for plastering, filling and even as a bonding paste. For layer thicknesses from 0 to 20 mm. Long working time. High filling capacity. Easy sanding.

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Field of application:

Interior walls and ceilings. For smoothing, plastering and rendering walls and ceilings made of concrete, mortar, brickwork, plasterboard or other suitable substrates. For filling holes, cavities and cracks. For filling joints in plasterboard, or other building or precast concrete panels.

Product description:

White powder with special additives, re-dispersible resins and selected aggregates. ARDEX W820 SUPERFINISH has a high filling capacity and is easily applied in both thin and thick layers. ARDEX W820 SUPERFINISH is water vapour permeable and is a suitable substrate for paints, dispersion plasters or other applications.

Preparation of the substrate:

The substrate must be dry, firm, resistant and free of dust, dirt or other agents that could impair adhesion. Elastic paints or varnishes, as well as poorly adhering paints or mortars or wallpaper, must be removed. ARDEX W820 SUPERFINISH can be applied directly to rigid absorbent substrates. Highly absorbent concrete substrates, or substrates that can be broken down, should be primed with ARDEX P51 diluted 1:3 with water. Thin, smooth, non-absorbent substrates, such as varnishes, plastic paints, ceramics, etc., must be primed with ARDEX P82 or ARDEX P4.

Instructions for use:

ARDEX W820 SUPERFINISH can be applied by hand or with pumping machines. If pumping machines are used, adjust the amount of water to a smooth consistency. When using spraying pumps, mix the ARDEX W820 powder in an approx. 40 L cylindrical bucket with a spiral rod, e.g. Colomix WK140 with water until a smooth, homogeneous, lump-free mortar is obtained. Between 11 - 12.5 L of water should be used for a 25 kg bag of powder. In manual applications, the mortar should be mixed as described above.

After approx. 1-3 min, the mortar should be mixed again. The consistency can be adjusted by slightly varying the amount of water. Once the mortar has been applied to the substrate, it should be spread and smoothed with a suitable trowel. After approx. 2-4 hours, depending on the absorption of the substrate, the thickness applied and the ambient conditions, the surface can be smoothed. If a new coat is required, the surface can be wetted with a sponge.

On large surfaces, ARDEX W820 should be applied at a minimum thickness of 2 mm. For repairs or patching, on primed or non-absorbent surfaces, the min. thickness shall be 1 mm. If successive coats are applied, wait until the previous coat has hardened and priming is not necessary. In case of doubt, carry out preliminary tests. When using pumps, the work interruption should not exceed 15 - 20 min (depending on the temperature). If longer breaks are planned, the machine must be cleaned ARDEX W820 SUPERFINISH must be used at temperatures above +5°C and below +30°C.


ARDEX W820 SUPERFINISH is water vapour breathable and is suitable for coating with dispersion paints, dispersion plasters, dispersion plasters and water-based plasters.

dispersion paints, dispersion plasters, paper, decorative plasters, varnishing techniques, etc...

The manufacturer's recommendations should always be taken into account, on gypsum substrates.


On plasterboard boards with suitable joints, it is not necessary to use tape. Do not mix with other materials. Do not use material that has started to harden. Clean pumps, buckets and tools after use, as material residues can shorten the working time of the next mix.

Recommended pumping and spraying machines:

PFT Remo Powercoat Knauf PFT GmbH & Co KG Postfach 60 97343 Iphofen.

GRACO N.V Industrieterrein Qude Bunders Slakweidestraat 31 B-3630 Maasmechelen

J. Wagner GmbH Otto Lilien-Straße 18 88677 Markdorf

Putzmeister Mörtelmaschinen GmbH Max Eyth Straße 10 72631 Aichtal

Technical data

  • Mixing ratio: Approx. 11-12.5 litres water : 25 kg powder. Represents 1 vol. water : 2 vol. powder.
  • Density: Approx. 1.1 kg/litre.
  • Density of the mortar when fresh: Approx. 1.45 Kg/litre.
  • Yield: Approx. 1,1 Kg powder/m²/mm.
  • Working time (20°C): Approx. 3 hours.
  • Painting and bonding: When dry. 
  • Compressive strength: Approx. 4 N/mm².
  • Flexural strength: Approx. 2 N/mm².
  • pH-value: Approx. 7
  • Packaging: 25 kg bags.
  • Storage: Approx. 12 months in a dry place in its original closed packaging.

Product Details

Single component
Synthetic plaster
Wall and ceiling
Drying time


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