Bonding Agent For Concrete Toppings

Cemkey Concentrate is used for bonding Portland Cement screeds and renders to brick, concrete and concrete masonry without any need to hack the surface to obtain a bond. May be used on new or old surfaces.

Cemkey Concentrate can also be added to the mixing water to improve resistance to trace acids and alkali, as well as reducing surface dusting.


Cemkey Concentrate allows the laying of new concrete screeds and renders, without the need to hack the existing surface to obtain a bond.


  1. No hacking to obtain a bond.
  2. Can be used for new work or repair work.
  3. Will adhere to most sound surfaces.
  4. Faster application of screeds and renders.
  5. Resists trace acids and alkali.


Used as a bonding agent: 5m2 to 12m2 per litre. Coverage is dependent on the roughness and porosity of the existing surface.


Used as a bonding agent: Dilute 1 volume of Cemkey Concentrate with 1 volume of clean water.
For use with mixing water: Dilute 1 volume of Cemkey Concentrate with 6 volumes of clean water e.g. 3 litres of Cemkey Concentrate to 18 litres of water per 40kg bag of Portland Cement.



  1. Surface to be treated must be structurally sound, free from oil, grease, paint and dirt, which may interfere with the bond of the material.
  2. Dilute Cemkey Concentrate with equal volume of water.
  3. Apply Cemkey Concentrate solution with stiff brush, broom or squeegee, ensuring that a continuous coating covers the surface, without pools or puddling on horizontal surfaces. For very dry or porous surfaces 2 coats may be necessary.
  4. Allow the Cemkey Concentrate coating to become tacky before laying the screed or render.


  1. Dilute Cemkey Concentrate with 6 volumes of water as per mixing instructions and use the solution as total mixing liquid.
  2. Dry mix required materials.
  3. Add Cemkey Concentrate solution and follow normal mixing and placing routine.
  4. Curing is essential to ensure that the screed or render reaches full strength, and this operation should be carried out as soon as the surface will allow.


Floor screeds should have a minimum thickness of 38mm and should be correctly designed to withstand the workload to which they will be subjected. To increase the resistance of the screed or render to trace acids or alkali, use Cemkey Concentrate diluted at the rate of 1 volume Cemkey Concentrate to 2 volumes of clean water. Clean all tools in fresh water before material hardens or dries.


Cemkey Concentrate is packed In 1 litre - 2.5 litre - 5 litre bottles - 20 litre pails - 210 litre drums


Cemkey Concentrate is not a waterproof material, nor is it suitable for use under conditions where continuous water is present.


For your nearest stockist or additional technical information for CEMKEY CONCENTRATE or any other of our wide range of adhesives, sealing compounds, concrete admixtures and additives for the construction industry contact CEMIX PRODUCTS LTD.


The above information is based on our best knowledge and we beleive it to be true and accurate, however, due to the variable nature of application the suitability of the product for the use intended is the sole responsibility of the user.

Comparison with traditional systems:

CharacteristicsTraditional SystemsGeoplast Reusable Formwork
Hindrance-Modular system
ResistanceLimitedUp to 60 kN/m2
Concrete adherenceRequires dismantling agentsBeing made of plastics, GEOTUB PANEL does not stick to concrete
Protection10%The best protection for the columns until the end of the operations
PlumbingRequires long operations and it is often inaccurateQuick and accurate thanks to the external structure that allows easy shoring and plumbing
Dismantling agentsRequiredNot required. Everitt Site Supplies recommend 'Kleen Kote' protection and release formula to maintain your forms in top condition.