ARDEX K 40 HB - Rapid Drying, High Build, Fibre Reinforced Levelling and Smoothing Compound

• Apply from 3mm to 40mm
• Fibre reinforced for strength and flexibility
• Walkable in approximately 2 hours, regardless of thickness
• Install resilient and timber floorcoverings in as little as 6 hours
• Fix tiles after 2 hours
• Extended 30 minute working time

ARDEX K 40 HB is a fibre-reinforced, high-build levelling and smoothing compound designed for applications ranging from 3mm to 40mm. It sets rapidly, allowing foot traffic in as little as 2 hours, regardless of thickness. Resilient floor coverings, including timber, can be installed after 6 hours for layers up to 5mm, and after 48 hours for thicknesses up to 40mm. Ceramic tiles can be laid as soon as the surface has achieved adequate strength and hardness, typically within 2 hours of application.

USE

ARDEX K 40 HB levels and smooths most internal subfloors in a single application, including concrete, screeds, stone, terrazzo, ceramic tiles, and suitable timber floors. It is also ideal for repairing uneven, damaged, or rain-affected concrete and correcting floor level tolerances.

MIXING

Mix 3½-3¾ litres of water per 22kg bag until smooth. Use an ARDEX mixing paddle with a slow-speed drill (600-1000 rpm). Adjust water for thick layers or cold conditions.

APPLICATION

Apply at temperatures above 5°C. Pour and spread using a pin steel trowel. Fresh material can be blended into existing applied areas within 30 minutes. Protect from direct sunlight and drafts to prevent premature drying.

APPLICATION OVER UNDERFLOOR HEATING

Ensure screeds are laid per BS 8204-1 and BS EN 1264. After commissioning and thermal cycling, reduce heating to room temperature (min 15°C) before applying ARDEX K 40 HB. Gradually return to operating temperature to avoid thermal shock. Can also encapsulate undertile heating cables before tiling.

COVERAGE

A 22kg bag of ARDEX K 40 HB covers approximately 4m² at 3mm thickness (1.88kg/mm/m²). Coverage may vary on rough or uneven surfaces, requiring additional material.

STORAGE AND SHELF LIFE

Store ARDEX K 40 HB in unopened packaging, off the ground, in a cool, dry place, and protected from drafts. When stored correctly, it has a 12-month shelf life from the date on the packaging.