To prevent waterproofing membranes and topical coatings from blistering or delaminating over damp or green concrete, Xpress Primer H2O Plus Primer forms a single-component vapour barrier that locks down residual substrate moisture. Unlike traditional epoxy vapour barriers, this water-resistant primer stops moisture without altering the surface profile, preserving the original texture of your screed, render, or concrete so overlaid finishes can achieve their intended mechanical bond.
Xpress Primer H2O Plus Primer is applied as a neat, single-coat liquid that penetrates mineral substrates. As it cures, it changes colour from milky white to a slight green tinge, finally drying completely clear to show it is ready for overcoating. This built-in visual indicator helps installers avoid premature membrane application, which can trap uncured moisture and lead to system failure. When used as a standalone sealer over screeds and renders, the primer blocks mineral migration to reduce efflorescence. On bare concrete, it seals the pores to prevent carbonation, protecting the reinforcing steel from structural degradation.
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.
Yes, Gripset Xpress Primer H2O Plus is specifically formulated for use over damp and green concrete or mineral substrates. It forms a vapour barrier to prevent blistering and delamination caused by residual moisture.
Finishes can be applied after only 1 hour, provided the primer is dry. The unique colour-changing formulation transitions from milky white to a slight green tinge, then dries clear, indicating it is ready for overcoating.
No, Gripset Xpress Primer H2O Plus is not for areas with continuous sources of rising moisture or negative hydrostatic pressure. For active moisture issues, you need to use Gripset E60.
Yes, as a standalone sealer over screed and render, it reduces the incidence of efflorescence. It also acts as a standalone sealer to prevent carbonation of concrete surfaces.
| Application | Key benefit | Primary trades |
|---|---|---|
| Vapour barrier under membranes and coatings | Prevents blistering and delamination of finishes due to residual moisture, even on damp or green concrete. | Waterproofers, tilers, builders |
| Sealing screeds and renders | Reduces incidents of efflorescence, ensuring a cleaner finish and reducing callbacks. | Renderers, tilers, concrete contractors |
| Preventing concrete carbonation | Acts as a standalone sealer, protecting concrete from atmospheric carbonation. | Concrete contractors, builders, renovators |
| Fast-track project schedules | Allows overcoating with finishes after only 1 hour, improving site efficiency. | All trades requiring fast turnaround |
Wear safety shoes, overalls, gloves (nitrile rubber recommended for intermittent contact), and safety glasses.
Natural ventilation is adequate under normal use conditions.
Store in original unopened packaging for up to 12 months. Keep in a cool, dry, well-ventilated area at room temperature, out of direct sunlight, and avoid freezing conditions. Dispose of material and containers according to local regulations.
Proper surface preparation is crucial for adhesion and long-term performance. This primer is designed for mineral surfaces only.
Surface prep: Ensure all surfaces are clean, sound, and free from loose material, dirt, dust, oil, grease, wax, laitance, curing compounds, release agents, or existing coatings. Mechanically remove structurally unsound layers by grinding or abrasive blasting. For masonry, point flush any voids, holes, or cracks. Building surfaces must be fit for purpose and installed to manufacturer’s recommendations.
Specific concrete prep: High MPa concrete or burnished/steel floated surfaces that show no water absorption must be mechanically abraded and roughened to facilitate primer absorption.
Active moisture: Substrates with active moisture or continuous rising damp require treatment with Gripset E60 before any priming or overlay.
Primer: Not required. Gripset Xpress Primer H2O Plus is the primer.
| Property | Value |
|---|---|
| Form | Thin Liquid |
| Wet Colour | Milky White |
| Transition Colour | Slight green tinge |
| Dry Colour | Clear |
| Solubility In Water | Miscible |
| Specific Gravity | 1.01 |
| pH | 8 |
| Coverage Rate | 1 litre / 6 m² per coat |
| Dry Time | 1 hour @ 23°C / 50% RH |
| Shelf Life | 12 months |
| Packaging | 15 litre pails |
| Application Temperature Range | 5°C to 35°C |
Here are some common examples on where Gripset Xpress Primer H2O Plus Primer used by our customers.
