EWI-333 SiSi Render Primer - 21kg-1

EWI-333 SiSi Render Primer – 21kg

£58.03 (incl VAT)

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EWI-333 Silicone Silicate (SiSi) Primer is a deep-penetrating primer used to prepare the substrate prior to the application of Silicone Silicate render. It bonds dusty surfaces, regulates absorptive capacity and reduces the required quantity of render – all without compromising breathability. SiSi primer can be pigmented according to match the colour of the render.

  • Waterproof
  • Frost-proof
  • Vapour permeable
  • Increases groundwork adhesion
  • Facilitates render application
  • Solvent-free

About SiSi Render Primer

Our SiSi Render Primer is designed for use before our silicone silicate render. It ensures that the render will adhere properly to the basecoat mesh layer, allowing for a long-lasting render finish. You can match the colour of your primer to the render to ensure a highly pigmented finish. SiSi Render Primer is:

  • Waterproof
  • Frost-proof
  • Vapour permeable
  • Increases groundwork adhesion
  • Facilitates render application
  • Solvent-free

SiSi Primer is based on potassium water glass and water dispersion of silicon resin, designed for silicate and silicon plaster. The product strengthens the substrate and limits its absorptive capacity without compromising its breathability. SiSi Primer facilitates rendering plaster coats and enhances their adhesion to substrates. EWI Pro Silicone Silicate primer is used after adding the reinforcement layer to the insulation or the substrate. It facilitates the application of Silicone Silicate Render, ensuring a finish that lasts.

Applying SiSi Render Primer

Substrate preparation: All substrates must have appropriate load-bearing capacity. They must be compact, stable, even and free of: dust, grease, anti-adhesive agents, remaining paint, mould, algae, moss etc., scratches and salt efflorescence. Substrates must be uniformly dry. All contamination resulting from grease, oil, anti-adhesive agents should be cleaned by washing with water and detergent and all organic growth should be removed with a wire brush.

Scratched and cracked surfaces should be repaired with levelling mortar. Ensure that any mortar applied is dried and well-bonded.

Product preparation: mix thoroughly before use. The product must not be thinned with water or any other materials.

Application: Apply EWI-333 uniformly to the substrate by using a roller to paint it on. Allow to dry before application of other materials. Works must not be carried out at temperatures below 5℃. Works must not be carried out during rain or snow, or in strong winds or direct sunlight without special shields to limit exposure to weather conditions. Recently rendered walls must be protected against such elements.

Application Conditions:

  • Application temperature (air, substrate, materials): from +5°C to +25°C
  • Coat drying time: approx. 4 hours
  • Time to leave before rendering: approx. 24 hours after priming
  • Colour: white
  • Quantity to be used: approx. 0.2-0.3 kg/m2 depending on substrate structure and absorbency)

Technical Specifications 

  • Composition: Potassium Silicate dissolved in water as well as acrylic resin, quartz aggregate and pigments
  • Bulk density: approx. 1.50 g/cm3


Wash tools immediately with clean water.

Safety Measures for SiSi Render Primer

Avoid contact with skin. Wear eye protection. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. After contact with skin, wash with water. Wear suitable protective gloves and clothing.


Shelf life: up to 12 months from the date of manufacture. Keep dry and in the original containers at a temperature ranging between 5℃ – 25℃.

SiSi Primer Packaging 

7kg/21kg plastic containers

Compliance with Standards

European Technical Approval No. ETA-07/0192 and European Technical Approval No. ETA-07/0118

SKU: EWI-333-21
Weight 21 kg


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