Gripset Xpress Multi Pro Membrane

Gripset Xpress Multi Pro is a fast-curing, water-based elastomeric waterproofing membrane for exposed roofs, balconies, parapets and under-tile wet areas. It is designed for jobs where slow drying, early rain or water ponding can delay the next stage. The cured membrane is UV-resistant and suitable for light foot traffic in an appropriately specified exposed system, while also accepting compatible tiles, screeds and toppings.

Why choose Xpress Multi Pro?

Speed and early water resistance are the reasons to choose Xpress Multi Pro over a conventional water-based liquid membrane. It can be recoated after approximately 1–2 hours, develops ponding-water resistance after approximately 3 hours and reaches full cure in about 24 hours under standard conditions. Its flexible Class III membrane resists re-emulsification in permanently wet conditions after curing. This makes it a strong option for external waterproofing schedules affected by cooler weather and high humidity, provided the surface and application conditions are suitable.

Choosing between Gripset membranes: Gripset P39 is another flexible, UV-resistant membrane for suitable exposed or tiled areas. Xpress Multi Pro is especially valuable when early ponding resistance and shorter cure windows are priorities. For fast under-tile waterproofing that will be covered rather than left exposed, compare Gripset 38FC.

Where to use it

• Exposed roof waterproofing: suitable roofs, parapets and external building surfaces requiring a UV-resistant membrane finish.
• Balconies, decks and podiums: exposed or covered waterproofing systems subject to weather and normal building movement.
• Roofs beneath screeds or toppings: a waterproofing layer that can receive a compatible protective topping system.
• Bathrooms, laundries and tiled wet areas: a flexible membrane beneath compatible tile finishes on prepared walls and floors.

Performance and coverage

• Recoat: approximately 1–2 hours.
• Early ponding-water resistance: approximately 3 hours.
• Full cure and flood-testing window: approximately 24 hours.
• Flexibility: greater than 300% elongation, Class III to AS 1145.3.
• Tensile strength: greater than 1 MPa to AS 1145.3.
• Under-tile membrane: at least 2 coats using a total of 1.5 L/m² to achieve a minimum 0.8 mm dry film thickness. A 15 L pail covers approximately 10 m² on a suitable smooth substrate.
• Exposed, light-trafficable membrane: at least 3 coats using a total of 2.0 L/m² to achieve a minimum 1.0 mm dry film thickness. A 15 L pail covers approximately 7.5 m² on a suitable smooth substrate.

Drying times are based on approximately 23°C and 50% relative humidity. Low temperatures, high humidity and substrate porosity can change cure times and consumption. The correct film thickness is important: a thin coating should not be treated as an equivalent exposed membrane system.

Compatible substrates and primers

Gripset Xpress Multi Pro can be installed on suitably prepared concrete, render, masonry, compressed fibre-cement sheeting, plasterboard, wet-area timber sheeting, external-grade plywood and aerated concrete panels or blocks. The surface must be sound, clean and free from dust, laitance, curing compounds, oils and loose coatings.

• Porous mineral surfaces: use Gripset GP Primer as the compatible absorbent-surface primer.
• Smooth, non-porous surfaces: use Gripset OP Primer where specified.
• Green or damp mineral substrates with residual moisture: Xpress Primer H2O Plus is designed to prepare compatible surfaces for this membrane without waiting for a conventional dry-substrate condition.
• More demanding slab moisture or rising-damp conditions: Gripset E-60 may form part of the specified moisture-control system. Xpress Multi Pro itself is not a negative-hydrostatic-pressure membrane.

Junctions, penetrations and finishes

Detail changes of plane, movement zones, waste outlets and pipe penetrations before coating the wider area. Compatible Gripset components include Elastoproof B10/B50 Joint Band, Elastoproof Corners, Base Collars and BRW PF Tape, selected to suit the joint or penetration.

For direct tiling, use a compatible polymer-modified cement-based tile adhesive such as Gripset C-Lite, C-Mastic or C-Rubber. Compatible screeds and toppings can be formed using Gripset C-Bed or a cementitious topping system incorporating Gripset 11Y where appropriate.

Important limitations

• Not for areas subject to negative hydrostatic pressure.
• Not suitable for areas exposed to solvent or petroleum spills.
• Do not apply when rain is imminent or when surface temperatures are below 5°C or above 30°C. Early water resistance does not mean the membrane can be applied during rain.
• Any subsequent finish coating must be solvent-free and compatible with the membrane.
• Exposed light-foot-traffic use requires the appropriate three-coat film build; it is not a general-purpose vehicle or heavy-traffic coating.