Residual moisture in concrete and mineral surfaces often delays critical follow-on trades, risking membrane blistering or coating delamination. Gripset Xpress Primer H2O Plus is a 1-component vapour barrier primer engineered to rapidly form a protective layer over damp or green concrete. This allows overcoating with finishes in just one hour, visually confirmed by its unique colour-changing indicator.

Why this product exists

Gripset Xpress Primer H2O Plus was developed as a unique, single-component solution for managing residual moisture on concrete and mineral substrates. Its core purpose is to prevent blistering and delamination of membranes and coatings, common issues when applied over damp surfaces. Crucially, it forms this vapour barrier without altering the surface profile, which means subsequent finishes bond correctly and maintain their intended appearance. It also acts as a standalone sealer, preventing concrete carbonation and reducing efflorescence on screeds and renders.

The numbers that matter

  • 1-component formulation: Simplifies application by eliminating mixing ratios and pot-life concerns. This removes a common source of on-site error and waste.
  • 1-hour drying time: At 23°C and 50% RH, this rapid drying window significantly accelerates project timelines, allowing membranes or coatings to be applied within a single work shift.
  • Colour-changing indicator: Transitions from milky white to a slight green tinge, then dries clear. This visual cue provides a clear, unmistakable signal that the surface is ready for overcoating, eliminating guesswork and reducing the risk of premature application.
  • 1 litre / 6 m² coverage: A single coat at this rate provides the necessary vapour barrier and sealing performance, offering efficient material use for critical preparation.

What it's like to use

Application is straightforward: Xpress Primer H2O Plus is used neat, without dilution. Apply a single coat using a brush or medium nap roller, ensuring full coverage. The product transitions from milky white to a subtle green, then dries clear, indicating readiness for overcoating. Clean tools with water while the primer is still wet. To maintain system integrity, install subsequent finishes shortly after the primer has dried.

Where this product excels

  • Fast-tracking damp concrete slabs: For projects requiring quick turnaround, it allows the application of membranes or coatings over damp and green concrete or mineral surfaces within an hour, preventing moisture-induced blistering and delamination.
  • Preventing concrete carbonation: As a standalone sealer, it forms an effective barrier to protect concrete from carbonation, extending its lifespan.
  • Reducing efflorescence on screeds and renders: Applied over screeds and renders, it minimises the unsightly and damaging effects of efflorescence by sealing the substrate.

How it fits in a real system

This primer typically serves as the critical first step in waterproofing or flooring systems over concrete and mineral substrates, especially when residual moisture is a concern. It prepares the surface to accept subsequent layers like the Gripset Xpress Multi Pro Membrane, ensuring optimal adhesion and system performance. Its fast-drying nature means the primer layer is established quickly, allowing the next trade to proceed without significant delay.

Choose this when

  • When you need to fast-track membranes or coatings: Its 1-hour dry time enables quick progression to the next stage of work on damp or green concrete.
  • When applying over damp concrete or mineral surfaces: It effectively forms a vapour barrier against residual moisture, preventing blistering and delamination of overlaid finishes.
  • When aiming to prevent concrete carbonation: Use it as a standalone sealer to protect concrete elements.
  • When reducing efflorescence on screeds and renders is critical: Apply it to seal and mitigate salt migration.

Don't use this when

  • Not for: Application below 5°C or above 35°C surface/ambient temperatures.
  • Not for: Application when rain is imminent.
  • Not for: Areas with continuous sources of rising moisture, active moisture, or negative hydrostatic pressure. For these conditions, use Gripset E60.
  • Not for: Non-concrete or non-mineral surfaces.
  • Not for: Un-abraded high MPa concrete or burnished/steel floated concrete without prior mechanical roughening.

Gripset Xpress Primer H2O Plus versus Gripset E-60 Primer

Gripset Xpress Primer H2O Plus is designed for rapid control of residual moisture on damp or green concrete, forming a vapour barrier in just one hour without altering the surface profile. This makes it ideal for fast-tracking projects where the substrate is simply damp from recent construction or cleaning. In contrast, Gripset E60 is specifically formulated for treating active moisture, rising damp, or areas under negative hydrostatic pressure, providing a robust solution for more challenging and persistent moisture problems. Choose Xpress Primer H2O Plus for speed and residual moisture control; opt for Gripset E60 when battling active water ingress.