Comparing Different Primers for Various Substrates

Selecting the correct primer is crucial for ensuring optimal adhesion, durability, and performance of flooring systems on various substrates. This comparison focuses on the correct selection of primers for concrete, sand and cement screed, anhydrite screed, flooring grade asphalt, and timber. We will consider epoxy-based, SBR-based, acrylic-based, and moisture vapor suppressant primers, detailing their technical characteristics and the required preparation for each substrate type.

Substrates and Required Preparation



  • Ensure the surface is clean, dry, and free from dust, grease, and contaminants.
  • Use mechanical methods such as grinding or shot blasting to remove any laitance or weak surface material.
  • Repair any cracks or defects before priming.

Sand and Cement Screed


  • Clean the surface thoroughly to remove dust, debris, and loose particles.
  • Ensure the screed is fully cured and dry.
  • Smooth any rough areas with mechanical methods if necessary.

Anhydrite Screed


  • Remove any surface laitance by sanding.
  • Ensure the screed is fully dry and moisture content is within acceptable levels.
  • Vacuum the surface to remove all dust and debris.

Flooring Grade Asphalt


  • Clean the surface to remove any dust, oil, or grease.
  • Ensure the asphalt is stable and free from defects.
  • Roughen the surface slightly if it is very smooth to improve adhesion.



  • Ensure the timber is clean, dry, and free from any oils, waxes, or finishes.
  • Sand the surface lightly to create a key for the primer.
  • Remove all dust and debris before applying the primer.

Technical Comparison of Primers

Epoxy-Based Primers


  • High adhesion strength.
  • Excellent chemical and moisture resistance.
  • Can act as a moisture barrier.


  • Concrete: Ideal for high-traffic areas and where a moisture barrier is needed.
  • Sand and Cement Screed: Provides strong adhesion and resistance to wear.
  • Anhydrite Screed: Suitable if moisture levels are controlled.
  • Flooring Grade Asphalt: Good for areas requiring chemical resistance.
  • Timber: Effective for creating a stable, moisture-resistant base.

Preparation Compatibility: Requires thorough preparation, including moisture testing and ensuring a clean, dry surface.

SBR-Based (Styrene Butadiene Rubber) Primers


  • Good flexibility and adhesion.
  • Water-resistant.
  • Enhances the bond between substrates and subsequent layers.


  • Concrete: Effective for improving adhesion and flexibility.
  • Sand and Cement Screed: Ideal for enhancing bonding, especially in areas subject to movement.
  • Anhydrite Screed: Suitable with correct surface preparation.
  • Flooring Grade Asphalt: Can be used if flexibility is required.
  • Timber: Useful for improving adhesion and providing a flexible base.

Preparation Compatibility: Requires clean and dust-free surfaces. Moisture content should be monitored.

Acrylic-Based Primers


  • Fast-drying.
  • Easy to apply.
  • Good adhesion and flexibility.
  • Suitable for both porous and non-porous substrates.


  • Concrete: Quick-drying solution for priming before applying self-levelling compounds.
  • Sand and Cement Screed: Good for general use, providing adequate adhesion.
  • Anhydrite Screed: Suitable with proper surface preparation.
  • Flooring Grade Asphalt: Can be used for light traffic areas.
  • Timber: Good for priming before applying paint or other finishes.

Preparation Compatibility: Generally requires less intensive preparation but still needs a clean, dry surface.

Moisture Vapor Suppressants (MVS)


  • Specifically designed to control moisture vapor emission.
  • Creates a barrier to prevent moisture-related issues.
  • Can be combined with other primers for enhanced performance.


  • Concrete: Essential for areas with high moisture content.
  • Sand and Cement Screed: Useful in situations where moisture levels are uncertain.
  • Anhydrite Screed: Necessary if there is a risk of moisture issues.
  • Flooring Grade Asphalt: Can help control moisture-related problems.
  • Timber: Not typically used, but can be beneficial in damp environments.

Preparation Compatibility: Requires precise moisture testing and a clean surface to ensure effectiveness.


The selection of the appropriate primer depends on the specific requirements of the substrate and the conditions of the installation environment:

  • Epoxy-Based Primers are ideal for high-demand areas requiring strong adhesion, chemical, and moisture resistance.
  • SBR-Based Primers provide excellent flexibility and adhesion, making them suitable for substrates prone to movement.
  • Acrylic-Based Primers offer ease of application and fast drying times, suitable for general use on various substrates.
  • Moisture Vapor Suppressants are critical for controlling moisture levels, particularly in substrates like concrete and anhydrite screeds.

Proper substrate preparation is essential for ensuring the effectiveness of any primer, including cleaning, drying, and surface treatment as necessary.

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