Ardex K39 Extended Workability High Flow Levelling and Smoothing Compound extended information
Coverage: Approximately 7.4m² at 2mm thick per 22kg bag.
USE
ARDEX K 39 will level and smooth, in a single application, all uneven internal sub-floors including concrete, cement/sand screeds, anhydrite screeds etc.
SUBSTRATE PREPARATION
The surface must be hard, sound and free of dust, dirt and other barrier materials such as paint, lime coatings, plaster and adhesive residues etc. Use ARDEX DGR to remove polish, wax, grease, oil and similar contaminating substances. Laitance should be mechanically removed from concrete surfaces. In all cases where traces of adhesive residues are present these must be sound, well adhered and unaffected by water.
DAMP PROOF MEMBRANES
Direct to earth sub-floors must have an effective damp proof membrane. If the DPM is absent or damaged, or the substrate is damp consult the ARDEX DPM 1 C, or ARDEX DPM1CR datasheet for further information.
PRIMING
All surfaces must be primed. ARDEX P 51 Primer should be used on porous or rough surfaces, e.g. cement/sand screeds, mechanically prepared concrete, anhydrite screeds etc. Please consult the ARDEX P 51 datasheet for correct dilution rates.
ARDEX P 4 Primer and ARDEX P 82 Primer are both recommended for use on ARDEX DPMs for smoothing applications of between 3mm to 6mm in thickness, and on non-absorbent sub-floors when ARDEX K 39 is applied up to 10mm in depth e.g. power floated concrete, smooth pre-cast concrete and sound terrazzo, porcelain/ceramic/quarry tiles or natural stone. For thicknesses that exceed the above recommendations use ARDEX R 3 E blinded with ARDEX Fine Aggregate as the primer coat. When applying over flooring grade asphalt, the surface must be sound, cleaned with a suitable neutral cleaner, primed with ARDEX P 82 Primer and applied between 3-5mm thick.
MIXING
Use up to 5.5 litres of water per 22kg bag. Add the powder to the required amount of clean water in a clean mixing container whilst stirring thoroughly until a lump free mortar is produced. The use of an ARDEX mixing paddle
with a 10mm chuck slow speed (600-1000 rpm) electric drill makes light work of mixing. The mixed ARDEX K 39 should be applied within 40 minutes at 200C. This time is extended at lower temperatures and reduced at higher temperatures.
APPLICATION
Pour the mixed ARDEX K 39 mortar onto the prepared sub-floor and use a steel finishing trowel or float to spread the mortar and finish off. The mixed mortar will flow out and self smooth within its 40 minute working time. For the first 25 minutes of the 40 minute working time ARDEX K 39 will retain a workable wet edge. Due to the extended wet edge properties of ARDEX K 39, fresh applications of material can be easily smoothed/trowelled into existing pre-applied material for up to 40 minutes after application. The superior smoothing and levelling properties of ARDEX K 39 help to ensure the best possible finish with minimum effort. Spike rollers may be used if preferred but their use is not essential as an excellent finish is normally achieved with a trowel or a gauging tool depending on the depth of the application. Where levelling large surface areas it may be advantageous to pump ARDEX K 39.
NOTE: It is recommended that the floor covering is applied within 48 hours to avoid contamination of the floor, if not, the surface should be covered until the floor covering is laid.
APPLICATIONS OVER UNDERFLOOR HEATING
The sub floor should have been laid in accordance with BS 8204 Part 1. The underfloor heating system should have been commissioned in accordance with the manufacturer’s instructions and in accordance with BS 8204 Part 1. Once thermally cycled and commissioned the underfloor heating system should be turned down to 150C before the installation of the ARDEX K 39, smoothing compound and final floor covering. The underfloor heating system should then be gradually re-commissioned to avoid rapid thermal shock and temperature variation.
THICKNESS
ARDEX K 39 can be applied from 1.5mm up to a maximum of 10mm in a single application. To utilise its free-flowing properties the minimum application thickness should be at least 2mm. A minimum thickness of 3mm should be applied on a non-absorbent sub-floor where an absorbent layer is required by the flooring adhesive. When applying ARDEX K 39 at thicknesses over 10mm, incorporate up to half a volume of ARDEX Coarse Aggregate. Mix the ARDEX K 39 as above without further addition of water. Mixes with aggregate may require a subsequent smoothing layer of ARDEX K 39.
DRYING AND HARDENING
A 5mm layer of ARDEX K 39 is walkable after 2 hours and ready to receive floorcoverings After 24 hours at 20°C. Layers up to 10mm are dry after 48 hours. Applications from 10 – 20mm require approximately 72 hours too dry, depending on site conditions. Where the applied mortar is subjected to rapid drying conditions, or where the installation of the floorcovering is delayed for longer than 48 hours, the surface should be covered to provide temporary protection against surface damage and contamination.
COVERAGE
Approximately 1.5kg ARDEX K 39 powder/ m2/mm, e.g. one 22kg bag will cover approximately 7.4m2 at 2mm thickness and 5m2 at 3mm thickness.
Ardex K39 technical data
Bulk density of powder approx. | 1.2kg/litre |
Weight of fresh mortar approx. | 1.9kg/litre |
Working time at 20°C approx. | 40 minutes |
Flow life at 20°C approx. | 25 minutes |
Compressive Strength: | |
After 1 day | 6.0 N/mm2 |
After 7 days | 22.0 N/mm2 |
After 28 days | 29.0 N/mm2 |
Tensile Bending Strength: | |
After 1 day | 2.0 N/mm2 |
After 7 days | 5.0 N/mm2 |
After 28 days | 8.0 N/mm2 |
EMICODE: | EC1+R |
Suitable for under floor heating | Yes |
There are no reviews yet.