TK11 – Key Coat Primer


TK11 Key Coat Primer is an ultra-high polymer and fibre modified flexible waterproofing primer. The product has excellent workability and adhesion properties, the product is applied in one-coat for fast application and can be applied in low temperatures. Used to promote adhesion and control suction on difficult substrates prior to a base coat or through coloured render.

Pack Size
25kg bag
Pallet QTY
40 bags
Application Tool
Sweep Brush / Stainless Steel Trowel
Suitable Substrate
Concrete, Clay,Light Weight Block, and Brick
Water Demand
Approx. 5-7 Ltr per 25kg bag
Pot Life
1 Hr +
5-8 M² per bag
Application Temperature
3˚c – 25˚c
Humidity Requirement
Less than 95%


All surfaces must be sound, clean, dry and free of any material which may impair adhesion. Do not apply to shiny surfaces. Scaffolding must be independently tied to allow for uninterrupted application. Any faults in the structure, particularly those which may lead to moisture penetration, must be rectified. Mask around the areas where material is to be applied. Masking tape must be removed before the material has dried out. Beads and expansion joints should be included as required by the substrate and BS standards and carried through all applied materials.

TK11 Key Coat Primer should be mixed 1 x 25kg bag with clean water at a rate of approximately 5.0 litres for application method 1 to 7.0 litres for application method 2. Add the water to the mixing container then add the powder slowly and mix using a suitable paddle or pan mixer, mix for 2 minutes, allow standing for 2 minutes then re-mix. This process allows the additives to dissolve and activate.

To avoid dampness and discolouration, rendering should be avoided below DPC or within 150mm of ground level.
If the substrate is very dry, water down with water, then apply when water has soaked in to the substrate and is not dripping down.
Method (1) Apply TK11 Key Coat Primer using a stainless steel trowel at approx. 2-3mm thick then run a brush horizontally across the surface to create a textured key.
Method (2) Apply TK11 Key Coat Primer as a slurry using a soft brush at approx. 2-3 mm thick.
Note: The choice of method is whichever the applicator feels is most suitable to their skill set. Specification Clauses relating to this product can be found in NBS Section M20 Rendering. BS 5262 Code of Practice for External Rendering and BS 8000-10 must be followed.

Strorage and Cleaning

When stored unopened in a dry place at temperatures above 5oC, shelf life is 12 months from date of manufacture.

All equipment must be washed with clean water immediately after use. Waste material should not be emptied into drainage systems.

Health and Safety

For further information, please request the material safety data sheet for this product.
The weather conditions for application and drying are critical. Do not apply if any of the following conditions are likely to arise during –
or in the first 24 hours following application:
o If frost is forecast, or in excessive wet conditions
o When Relative Humidity is above 95%
o In temperatures below +3ºC or above +25ºC
o If the elevation is in direct sunlight
o If the substrate is hot (at or above 30C) or below +3ºC
o Coverage rates are approx. and do not take into account wastage and uneven substrates
The render must be protected against heavy rain, direct sun or high wind in the first 24 hours after application. Sheeting the façade or the scaffold is advised to protect against this. For this particular product, if these parameters are not met, the product is at risk of, efflorescence and potential failure. It is the responsibility of the application contractor to manage and record the weather conditions during application and curing of the product.
To the best of our knowledge and belief, this information is true and accurate. However, as conditions of use of the product and the expertise of any labour involved are beyond our control, the end user must satisfy himself by prior testing that the product is suitable for his specific application if no spec has been provided for the project in hand. No responsibility can be accepted, nor any warranty given by our Representatives, Agents or Distributors. Products are sold subject to our Standard Conditions of Sale and the end user should ensure
that he has consulted our latest literature.

Download TK11 Product Datasheet


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