Ardex X 78 MICROTEC® Flexible Standard Set Semi-Pourable Floor Tile Adhesive

Key Features:

• Semi-pourable consistency – Ideal for solid bed fixing, especially with large format tiles
• High performance in wet areas – Perfect for use in swimming pools and other submerged environments
• Extended working time – 3-hour pot life and 60-minute open time for efficient fixing and reduced waste
• High coverage – Up to 5.6m² per 20kg bag at 3mm bed thickness
• Suitable for underfloor heating – Excellent flexibility and performance
• Internal & external use – Reliable in all environments, from pool interiors to surrounding paving

Suitable for External Use or Wet Areas
Yes, including swimming pools

Suitable for Use with Under Tile Heating
Yes

Bed Thickness
1-6mm

Pot Life
3 hours

Open Time
60 minutes

Adjustment Time
30 minutes

Grout After
24 hours

Coverage
Approximately 5.6m² at 3mm thick per 20kg bag

Product Type: Adhesives
Colour: Grey
Dimensions: 20kg
Application: Internal
Suitability: Pool Lining, Bathroom, Kitchen
Country of Origin: United Kingdom
Weight (Kg): 20kg

USE
ARDEX X 78 is ideal for fixing fully vitrified or porcelain tiles and other tiles with low porosity, as well as glass and porcelain mosaics and terrazzo. The BS EN 12004 C2 E designation for ARDEX X 78 classifies the adhesive as an “improved, cementitious adhesive with extended open time characteristics.”

The additional characteristics for ARDEX X 78, determined in accordance with BS EN 12004, are: a tensile adhesion strength of greater than 1 N/mm²; adhesion value greater than 1 N/mm² after water immersion, after heat aging, and after freeze-thaw cycling—making this product suitable for internal and external situations, including swimming pools. The mixed mortar has an easily workable, semi-pourable consistency to facilitate large-format floor tile fixing.

ARDEX X 78 adheres strongly to most construction materials such as concrete, cement and sand screeds, heated sub-floors, anhydrite screeds, and existing ceramic tiled surfaces.

SURFACE PREPARATION
The backgrounds and surfaces to receive the tiles must be clean, firm, and free of dust, dirt, oil, grease, or other barriers to adhesion. Ensure that the background has adequate drying time, as specified in BS 5385-3:2007, prior to fixing the tiles.

Install tiles in accordance with the relevant parts of BS 5385 and BS 8000: Part 11 (Workmanship on Building Sites). Backgrounds to receive ceramic tiles should be finished to Surface Regularity 1—i.e. any gap under a 2m straight edge must not exceed 3mm.

ARDEX X 78 can be applied to dry or moist surfaces, but moisture-sensitive materials must be dry and remain dry after fixing. ARDEX WPC Waterproof Protection System can be used prior to tiling to create a waterproof coating that protects moisture-sensitive backgrounds in wet locations.

MIXING
ARDEX X 78 powder is added to clean water in a clean container while stirring, and mixed thoroughly to give a semi-pourable, easily worked mortar. Using an ARDEX mixing paddle with a 10mm chuck variable-speed electric drill makes light work of mixing.

Mixing ratio by volume: approximately 2¾ parts ARDEX X 78 powder to 1 part water.
A 20kg bag requires approximately 7.2 litres of water.
Do not exceed the maximum water content. The consistency of the adhesive can be adjusted to suit site conditions and materials being fixed. Apply mortar at temperatures above 5°C. The pot life of mixed mortar is approximately 3 hours at 20°C.

APPLICATION
Apply the mixed mortar to the prepared surface with a trowel, then comb through with a suitably sized notched trowel in straight ribs to form a ribbed mortar bed.

Fix tiles within the open time of the adhesive. Press into place using a twisting and sliding action, ensuring solid bed fixing. ARDEX X 78 is classified as having an extended open time of not less than 60 minutes with freshly mixed material, when measured in accordance with BS EN 12004.

For optimal performance under typical UK site conditions, fix tiles within 40 minutes and adjust as necessary for up to 30 minutes at 20°C.

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