SBR Waterproof Bonding Agent

Thompson's SBR Waterproof  Bonding Agent is a multi purpose and flexible bonding agent and primer. Ideal when working on high abrasion floors.

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Water resistant bonding agent, primer & admixture

Improves water resistance, durability & flexibility

Can be used on internal & external rendering

Suitable for use on:

internal and external rendering

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m2 / litre


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  • All surfaces must be sound, clean and free from dust, grease, oil and loose materials
  • Surfaces with high suction should be dampened before application
  • Any excess water should be removed from the surface before application

Waterproofing Renders


  • For stable substrates:
    • Brush apply a coat of Bonding Primer 1
  • For weak, porous substrates: 
    • Apply Bonding Primer 2 by brush, working into the surface. Leave to harden (min. 16 hours, max 3 days) 
    • Brush apply Bonding Primer 1
  • Apply first coat of render whilst Bonding Primer 1is still tacky

Applying Render

Whilst Bonding Primer 1 is still tacky, apply a render of Mix A at a minimum thickness of 6mm. Allow to harden for 5-6 hours. Scratch this coat to give a key for the finishing coat.

Apply second render of Mix A to a maximum thickness of 6mm


Dampen the surface if necessary, then brush apply Bonding Primer 1. Lay the screed whilst the primer is still tacky
Select mix design based on screed type and application thickness
Mix the screed with enough gauging liquid to give a good working consistency
In the first 48 hours after application, prevent the mixes from drying out by covering with polythene sheeting, damp hessian or by misting with water

Clean all equipment with water immediately after use