Areas of Application
- Suitable for walls and floors
- Intended for indoor use
- Ideal for waterproofing wet and damp areas such as bathrooms and showers, as well as other rooms with moisture exposure classes I to II
- For moisture-sensitive surfaces: gypsum plaster, gypsum, drywall, calcium sulfate screed, and others
- For absorbent mineral surfaces: lime, lime-cement, and cement plasters, cement boards, cement screeds, concrete, aerated concrete, and others
- Provides waterproof, elastic protection for substrates before applying ceramic tiles and natural stone (together with Knauf Flächendichtband surface sealing tape and cement-based tile adhesives, such as Knauf Flexkleber)
- For elastic waterproofing under tiles and panel coverings when the substrate is subjected to high thermal loads (e.g., for underfloor and wall heating)
Features of Knauf Flächendicht Waterproofing Coating
- Covers cracks up to 2 mm thick, providing high security even in case of subsequent substrate cracks
- High waterproofing capacity prevents water penetration into the substrate
- Easy to use: apply with a plastic roller, lambskin roller, brush, or glue brush
- Ready to use and solvent-free. Compatible with silicone
- Suitable for moisture exposure classes A (wall) according to Building Standards List A (abP) and A0 according to ZDB leaflet “Composite Seals,” as well as according to ETAG 022 for waterproofing walls and floors in wet areas, Part 1: liquid-applied waterproofing. Can be used for internal waterproofing for water exposure classes W0 I to W2 I on walls and W0 I to W1 I on floors according to DIN 18534
Technical Data
- Processing / substrate temperature: from +5°C to +25°C
- Wet layer thickness: approx. 0.8 mm
- Total dry layer thickness: approx. 0.5 mm
- Thinning when used as a primer: 1:4 with water
- Thinning when used as waterproofing: undiluted
- Drying time when priming: approx. 3 hours
- Drying time when sealing: each coat 4 - 6 hours
- Drying time before tile application: approx. 12 hours
- Consumption per coat per m² on rough, porous substrates: approx. 450 to 700 g/m²
- Consumption per coat per m² on smooth surfaces: approx. 350 to 500 g/m²
- Total consumption per m² on rough, porous substrates: approx. 900 to 1400 g/m²
- Total consumption per m² on smooth surfaces: approx. 700 to 1000 g/m²
- Packaging: 5 kg sealing tape, sufficient for approx. 3.5 to 5.5 m²
- Temperature resistance after drying: from -20°C to +80°C
*Values at 23°C and 50% relative humidity.
**Depends on the absorption of the surface.
Substrate
The surface must be firm, clean, dry, and free of oils, fats, and release agents. Remove dust, paint, and mortar residues and others. Fill cracks and joints in the substrate. Irregularities in the substrate must not be leveled with Knauf Duschdicht. Before waterproofing, surfaces must be impregnated with Knauf Reparaturspachtel (for cement-based substrates, inside and outside) or Knauf Uniflott (for gypsum-based substrates, only inside). Strengthen chalky substrates with Knauf Tiefengrund. Roughen the surface of the applied waterproof paint, remove dust, and prime with Knauf Tiefengrund. Prime porous substrates like aerated concrete with Knauf Spezialhaftgrund.
Moisture penetration from the substrate, e.g., from soil or through external walls, must be excluded. Residual moisture in cement screeds must not exceed 2%, in calcium sulfate screeds no more than 0.5%, in plasters no more than 1%, and in heated substrates no more than 0.3%. Plastering must be carried out in accordance with DIN 18550.
Application
- For sealing with Knauf Flächendicht, a primer layer is required (not necessary if previously primed with Knauf Tiefengrund or Knauf Spezialhaftgrund) and at least two fully covering layers. The entire coating must have the specified minimum material consumption at every point (see section: Technical Data). The safest way to achieve this is with a roller.
- Before use: Stir Knauf Flächendicht well.
- Priming: Prime the substrate with Knauf Tiefengrund or Knauf Spezialhaftgrund (preferably) or with diluted Knauf Flächendicht.
- Waterproofing (2 to 3 coats): Apply the first coat of waterproofing undiluted with a roller on the fully dry primer. A minimum of 3 coats with a thin or thick brush is required. The application must be dense (but not too thick) and even (recommended consumption, see overview table). In the area of the walls and corners, place the sealing tape (Knauf Flächendichtband) on the still fresh, first undiluted coat and press firmly. Similarly, seal pipes and floor channels with Knauf Dichtmanschetten. Apply the second and, if necessary, third coat only after the previous coat has completely dried. Color the second coat with Knauf Compact Color 2g.
- Minimum drying time: approximately 3 hours (at 20°C and 50% humidity). Drying time is extended at high humidity and low temperatures. For porous substrates, triple undiluted application is recommended. Observe the minimum application quantities (see table). Thick layers dry very slowly; therefore, the application of more thin layers is recommended.
- Tiling: Ceramic tiles or natural stone slabs can be laid on the hardened surface (at the earliest 12 hours after the last waterproofing coat). The coating must be adhered with waterproof, elastic adhesive (e.g., Knauf Flexkleber). Elastic joint material (e.g., Knauf Flexfuge schnell) should be used for grouting.