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Polyshield Roof Primer 5L

£63.00 Ex VAT
£75.60 Inc VAT

A fast-drying roof primer designed to deliver optimum waterproofing as part of the wider Polyshield system to very porous or friable exterior substrates including flat roofs and in green roof systems.

Roof Primer Coating

Polyshield Primer is a fast-drying exterior roof primer designed to prime very porous substrates. It should be applied before you apply the Polyshield liquid waterproofing membrane basecoat and topcoat.  

As a solvent-based roofing primer, it comes ready to use and easy to apply by brush or roller. 

Uses of Roof Waterproofing Primer

Polyshield Primer should be used as a roof primer coating on the following friable and porous substrates:

  • concrete
  • asbestos cladding / cement
  • fibreglass and GRP
  • weathered asphalt & bituminous surfaces
  • sheeting and guttering
  • wooden substrates - OSB/plywood & timber decks
  • EPDM rubber

Note: We recommend carrying out an adhesion test as per manufacturer’s instructions.

Primer for Green Roof Waterproofing

In a green roof system, you need to be completely confident in the waterproofing of the substrate. If it is a porous substrate, we recommend applying this primer before the Polyshield Basecoat liquid roof membrane. This ensures long-lasting primary waterproofing of your roofing substrate that can then take the green roof system build-up.

Note: We recommend that the Polyshield system is installed by an experienced contractor

Applying roof primer


Make sure you are wearing gloves, goggles and suitable protective clothing. Remove all debris, loose materials and plants from the roof substrate and ensure that outlets and gutters are clear. Using a pressure washer, clean the surface thoroughly to get rid of moss and algae. Once the substrate is clean, you should then dry it using rags or a squeegee and then let it dry naturally. You are now ready to apply the primer coating.


Stir the roof primer well before applying. Consult the manufacturer's technical datasheet for coverage rates and never thin this product.

You can now apply a generous coat of Polyshield Primer by brush or solvent-resistant roller. Once dry you can apply the basecoat of your Polyshield Liquid Roof Membrane, before embedding the Reinforcing Scrim as per manufacturer’s instructions. Once dry, you can apply the topcoat of Polyshield Roof Membrane.

We recommend working away from the newly coated area and towards your access point. Avoid walking on the newly coated surface whilst application is in progress.

Important note: Never apply in direct hot sunlight, or on frozen or damp surfaces. The temperature needs to be between 2°C and 35°C.

Drying Time   

This roofing primer will be dry under normal conditions in 2 - 4 hrs depending on humidity and temperature. It can be overcoated when dry.

Permagard - Providing Solutions. Inspiring Confidence.

Permagard are proud of our high quality and affordable roofing waterproof products and our Green roof systems. We provide professional products to DIYers. The Roof Primer is ideal for use with a green roof If you have any questions about your living roof specification, we can help. Read our Green Roof Construction Guide for more technical details or our introduction to green roofs. 


  • Fast-drying
  • Ready to use & easy to apply
  • Improves adhesion on difficult substrates
  • Suitable as a flat roof primer
  • Designed for use with Polyshield Liquid Roof Membrane
  • Rainwater immediately after application has no impact
  • Ensures topcoat delivers optimum waterproofing performance
  • Ensures stabilisation of highly porous roof substrates