Ardex A18 – 25Kg

£47.65 exl. VAT

Per Unit


SKU 45685141215610655 Category

Screed Bonding Cement with Colour Indicator.

  • For internal and external use
  • Produces a slurry ideal for bonding ARDEX Screed Cements
  • High adhesion strength maximises the bond between the screed and the substrate
  • Colour change reduces the risk of the application of screeds into dry bonding slurries
  • 60 minute pot life & 15 minute open time

You May Also Need...


Ardex A18 – Screed Bonding Cement with Colour Indicator

Ardex A18 – Screed Bonding Cement with Colour Indicator is a green powder with aggregates and specially formulated additives which, when mixed with water,
produces a slurry ideal for bonding Ardex Screed Cements. The bonding slurry changes colour as it dries, indicating if it remains open to receive the Ardex Screed Cement.

Ardex A18 – Screed Bonding  Uses

Ardex A 18 is used for producing bonding slurries for application over concrete and cement/sand screeds. It is suitable for internal and external use, including swimming pools.
Ardex A 18 can also be used for joining daywork joints when a new bay is laid against a set and hardened screed, including screeds with underfloor heating systems.

Preparation of the substrate:

The substrate may be dry or damp (with no surface water) but must be rigid, clean and free of dust, grease and other barriers to adhesion. The use of Ardex DGR Degreaser is recommended for the removal of oils, waxes and any other barriers to adhesion, from the substrate. Concrete surfaces must be prepared using suitable mechanised equipment to expose the coarse aggregate and to remove all barriers to adhesion. All surface coatings must be removed prior to application.

Mixing Screed Bonding Cement with Colour Indicator:

Add the Ardex A 18 powder to clean water in a clean container, whilst stirring and mixing thoroughly to give a smooth, lump-free paste. The use of an Ardex
mixing paddle with a 10mm chuck variable speed electric drill makes light work of mixing. The mixing  proportions by volume are: 3 parts Ardex A 18 powder to 1 part
water. A 25kg bag of Ardex A 18 powder requires approximately 5.75 litres of water. The mixed Ardex A 18 slurry has a working time of approximately 60 minutes. Once the mortar starts to stiffen/set, do not add additional water to the mix.

Application of Screed Bonding Cement with Colour Indicator:

Apply Ardex A 18 to the substrate with a brush to a minimum thickness of 1.5mm. The screed cement must then be placed and compacted ‘fresh in fresh’ whilst the bonding slurry is still wet and workable; this is indicated by a dark green colour. After approximately 15 minutes the colour changes to light green, indicating the slurry has dried and an additional application will be required. Apply Ardex A 18 at temperatures above 5°C.

Not quite what you’re looking for? Click here to browse more of our Ardex range.

Want to see how Ardex A18 has been used? Click here to view a range of Ardex Projects.



For more than 60 years, ARDEX has been a quality leader for the flooring and tiling industries, the brand of choice for installers and distributors. ARDEX today is still an independent family-owned business. This means that in our permanent efforts to achieve market-shaping innovations, we have been able to retain our most important tradition: uncompromising quality. This is something we guarantee by applying the latest rigidly enforced quality assurance procedures, making it no coincidence that they are regarded as a premium partner of the construction industry. Strong internal growth and intelligent acquisitions in foreign markets have put the Group on the map with 53 subsidiaries and 3,000 employees on all continents. With its 14 major brands, the ARDEX Group generated a worldwide annual turnover in excess of 770 million euros in 2018. This marks an important milestone and they are becoming one of the world’s leading suppliers of high-quality specialist building materials.

Technical Information