ARDEX K15 HB High Build Levelling and Smoothing Compound Grey 25kg

• Product ID: 18282
• Suitable For: levelling concrete subfloors
• Area of use: INT
• Application Method: trowel
• Volume: 25KG
• Container Type: bag
• Type: concrete
• Colour: grey
• Brand: Ardex
• Manufactuer: Ardex
• Box Size: 1

Substrate Preparation

The surface must be hard, sound, and free from dust, dirt, and any barrier materials such as paint, lime coatings, plaster, and adhesive residues. A suitable degreaser should be used to remove contaminants like polish, wax, grease, and oil. Laitance must also be eliminated from concrete surfaces. Direct-to-earth subfloors require an effective damp proof membrane (DPM). If the DPM is missing or ineffective, consult the ARDEX DPM 1 C or ARDEX DPM 1 C R datasheet for guidance, or contact our Technical Support Team for assistance.

All surfaces must be primed: Use ARDEX P 82 or ARDEX P 4 primer for smooth, non-absorbent subfloors, such as power-floated concrete or smooth precast concrete. For porous or rough surfaces, like cement and sand screeds or scabbled concrete, ARDEX P 51 primer should be used. Refer to the Priming and Preparation Leaflet for the correct dilution rates. Note that ARDEX K 15 HB should not be applied over asphalt; consult the ARDITEX NA® or ARDEX FA 20 datasheets for advice.

Mixing and Placing

Add the powder to the required amount of clean water in a clean mixing container while stirring thoroughly until a lump-free mortar is achieved. The mixing proportions are approximately 4 to 4.25 liters of water per 25 kg bag. Use the minimum amount of water for thicker applications or in cold conditions, and ensure application occurs at temperatures above 5°C. An ARDEX mixing paddle with a 10mm chuck and a slow-speed electric drill (600-1,000 r.p.m.) is recommended for mixing. Mixed ARDEX K 15 HB should be applied within 30 minutes at 20°C; this time will extend at lower temperatures and shorten at higher temperatures. Note: ARDEX K 15 HB can be pumped using suitable floor screed mixer pump units. For pumping advice, including suitable equipment and techniques, please contact our Technical Support Team.

Application

Pour the mixed ARDEX K 15 HB onto the prepared subfloor and use a steel finishing trowel or ARDEX Pin Leveller to spread and finish the mortar. The mixed mortar will flow and self-smooth within the first 15 minutes of its 30-minute working time. Note: Depending on the thickness of the application, the inclusion of aggregate, the desired finish, and intended use, a final smoothing layer may be necessary—particularly for thin, resilient floor coverings applied over thin layers of ARDEX K 15 HB or when extra aggregate has been added. This is typically not required for coverings such as carpet, ceramic tiles, natural stone tiles, or wood blocks. Before applying a smoothing layer of ARDEX K 15, treat the surface of the ARDEX K 15 HB as a porous and absorbent subfloor.

Applications Over Underfloor Heating

Heated screeds must be installed in accordance with BS 8204 Part 1 and BS EN 1264. The underfloor heating system should be commissioned according to the manufacturer’s instructions and relevant standards. After commissioning and thermal cycling, the underfloor heating system should be set to room temperature, but not below 15°C, before installing ARDEX K 15 HB and the final floor covering. Gradually bring the heating system up to normal operating temperature to prevent rapid thermal shock and avoid wide temperature variations.