Ardex X 77 Adhesive – Flexible Standard set Wall & Floor Tile Adhesive

• Exceptional slip resistance – Fix any tile size or type without battens
• Long working time – 3-hour pot life and 60-minute open time for efficient installation
• High yield formula – Covers up to 8m² per 20kg bag, up to 40% further than many alternatives*
• Underwater-ready – Suitable for tiling swimming pools and other submerged areas
• Versatile use – Ideal for non-moisture sensitive natural stone and almost all tile types
• Wall & floor applications – Internal and external, including wet environments
• Underfloor heating compatible – Flexible and durable under thermal movement

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
Walls – 8 hours
Floors – 24 hours

Coverage
Approximately 8m² per 20kg bag using an 8mm x 8mm notch trowel

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

USE
ARDEX X 77 is ideal for fixing ceramic or fully vitrified tiles and other tiles with low porosity, as well as glass and porcelain mosaics, and terrazzo. The BS EN 12004 C2 TE S1 designation for ARDEX X 77 and ARDEX X 77 W classifies the adhesives as “improved cementitious adhesives with additional characteristics, reduced slip and extended open time”. ARDEX X 77 and ARDEX X 77 W have an extended open time of up to 60 minutes, twice the requirement of BS 12004, and double the slump resistance of ‘T’ classified adhesives. The additional characteristics for ARDEX X 77 and ARDEX X 77 W, determined in accordance with BS EN 12004, make these products ideal for fixing all types of ceramic tiles and mosaics in internal and external situations, including swimming pools.

The mixed mortar has a slump-free consistency with very high initial grab, enabling heavy wall tiles to be fixed, thus reducing the need for battens and spacers. ARDEX X 77 and ARDEX X 77 W adhere strongly to most construction materials such as concrete, cement and sand renders and screeds, heated sub-floors, brickwork and blockwork, gypsum plaster, plasterboard, and primed existing ceramic tiled surfaces.

SURFACE PREPARATION
The backgrounds and surfaces to receive the tiles must be clean, firm, free of dust, dirt, oil, grease, and other barriers to adhesion, as well as being strong enough to support the weight of the tiles being fixed. Ensure that the background has adequate drying time, as given in the relevant part of BS 5385, and is correctly primed, where required, 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 should not exceed 3mm. ARDEX X 77 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 protective coating that prevents water damage to floors and walls by protecting moisture-sensitive backgrounds in wet locations.

MIXING
ARDEX X 77 and ARDEX X 77 W powder should be added to clean water in a clean container while stirring, and mixed thoroughly to give a slump-free, easily worked mortar. The use of an ARDEX mixing paddle with a 10mm chuck, variable-speed electric drill makes mixing easy.
The mix proportions by volume are approximately: 2 parts ARDEX X 77 or ARDEX X 77 W powder to 1 part water. A 20kg bag of ARDEX X 77 or ARDEX X 77 W requires approximately 8.5 litres of water. Do not exceed the maximum water content. The consistency of the adhesive can be adjusted to suit site conditions and the materials being fixed.

The mixed mortar should be applied at temperatures above 5°C. The pot life of the mixed mortar is approximately 3 hours at 20°C.

APPLICATION
The mixed adhesive is applied to the prepared surface with a trowel and then combed through with a suitably sized notched trowel in straight ribs to give a ribbed mortar bed. The tiles should be fixed within the open time of the applied adhesive and pressed into place with a twisting and sliding action to ensure full contact.

For tiling to walls in dry internal locations, maximum practical contact between the tile and adhesive should be achieved. Tiles with a surface area less than 0.1m², but which weigh more per square metre than 70% of the background’s capacity to carry the weight, should be solidly bedded. Tiles with a surface area of 0.1m² or greater should also be solidly bedded.

When tiling floors, wet areas such as showers and swimming pools, or external areas, achieving a solid bed often requires buttering the backs of the tiles immediately before placing them into the ribbed bed, ensuring no voids are left underneath. The choice of notched trowel depends on tile size, surface profile, and the degree of coverage required.

ARDEX X 77 and ARDEX X 77 W are classified as having an extended open time of up to 60 minutes with freshly mixed material, in accordance with BS EN 12004. For best performance under typical UK site conditions, tiles should be fixed within 40 minutes and can be adjusted for up to 30 minutes at 20°C.

Return Policy: Please see our Terms and Conditions

Browse our FAQs for more information