Gripset Xpress Primer H2O Plus Primer

Gripset Xpress Primer H2O Plus is a one-component vapour-barrier primer for damp or green concrete and other mineral substrates before compatible waterproofing membranes and coatings. It controls residual substrate moisture that could otherwise cause an overlaid membrane to blister or lose adhesion, without changing the existing surface profile.

When to choose it: H2O Plus is particularly useful under Xpress Multi Pro on suitable porous substrates with residual moisture. Where rising damp or negative hydrostatic pressure must be managed, compare the two-part Gripset E60 epoxy barrier rather than treating the primers as interchangeable.

How it works

Xpress Primer H2O Plus is applied as a one-component liquid that changes from milky white through a slight green tinge to clear as it dries. This colour change helps installers judge readiness for the next compatible coating. It can also be used as a standalone sealer to reduce concrete carbonation and the incidence of efflorescence on screeds and renders; those benefits are separate from its role as a residual-moisture primer.

Where to use it

• Substrates: Concrete, green concrete, concrete block, screeds, renders, masonry, aerated concrete, compressed fibre cement sheeting, and plasterboard.
• Overlaid systems: Recommended for priming porous surfaces prior to applying Gripset Xpress Multi Pro Membrane, as well as other overlaid membranes and coatings.
• Sealing applications: Standalone sealing for concrete carbonation protection and efflorescence control on sand-cement screeds and mineral renders.

Numbers that matter

• 1 hour dry time: Fast-drying formula (at 23°C and 50% relative humidity) that allows you to apply waterproofing membranes or decorative finishes with minimal downtime on-site.
• 1 litre per 6m² coverage: A reliable application rate for estimating material requirements over standard mineral surfaces, though actual coverage varies with substrate porosity.
• 1-component formulation: Ready to use straight from the pail without measuring, mixing, or pot-life limitations associated with two-part epoxy barriers.

Limitations

• Suitable for use over concrete and mineral surfaces only.
• Do not apply to substrates subject to active, continuous sources of rising moisture or negative hydrostatic pressure; these must be treated with Gripset E60.
• Do not apply when surface or ambient temperatures are below 5°C or above 35°C.
• Do not apply when raining or when rain is imminent.

Application and preparation

All substrates must be clean, sound, smooth, and free of laitance, curing compounds, release agents, existing coatings, and general contaminants. High MPa concrete, burnished concrete, or steel-floated concrete surfaces that show no water absorption must be mechanically abraded or roughened to ensure the primer can penetrate the pores. Apply one coat neat by brush or medium nap roller until full coverage is achieved. Do not dilute. To prevent site dust or debris from contaminating the primed surface, install overlaid membranes or finishes shortly after the primer dries clear.