For internal and external wet areas, balconies, and roofs where pooling water or UV exposure typically threatens membrane integrity, P39 Membrane provides a water-based hybrid polyurethane barrier. It cures to handle early water ponding and permanently wet conditions without re-emulsifying, protecting substrates including concrete, fibre cement sheeting, and wet-area timber sheeting.
P39 Membrane combines hybrid polyurethane chemistry with fibre reinforcement to achieve high elasticity and a low vapour transmission rate. This formulation prevents water absorption in constantly wet environments, such as laundries, bathrooms, podiums, and parapets. The cured film withstands light foot traffic and resists UV degradation on exposed external surfaces, or it can serve as an under-tile membrane beneath polymer-modified cement adhesives.
P39 Membrane bonds to common building substrates, provided they are primed correctly. Approved substrates include:
The membrane must be applied onto primed surfaces. Select the primer based on substrate conditions:
Critical joints, junctions, penetrations, and cracks must be sealed prior to applying the membrane. Use one of the following systems:
Yes, Gripset P39 is formulated for exposed applications on roofs and parapets. It provides outstanding weather and UV resistance, is light foot trafficable, and meets AS 4654.1 for external wet areas.
No, Gripset P39 will not re-emulsify once cured. It is designed to handle early water ponding and permanently wet conditions, which prevents failure in challenging areas like balconies or flat roofs under toppings.
Yes, Gripset P39 must be applied to primed surfaces. The correct primer depends on the substrate's condition; options include Gripset GP Primer for porous surfaces or Gripset E60 for damp surfaces with residual moisture.
No, Gripset P39 is not to be used in areas subject to negative hydrostatic pressure. Using it in such conditions will lead to membrane failure and water ingress.
| Application | Key benefit | Primary trades |
|---|---|---|
| Exposed roofs, parapets, and external surfaces | Outstanding weather and UV resistance for long-term protection, light foot trafficable. | Waterproofers, Roofers |
| Internal wet areas, bathrooms, laundries, and general tiled areas | AS 4858 compliance, elastomeric to accommodate movement, low vapour transmission to prevent moisture ingress. | Tilers, Waterproofers |
| Balconies, decks, podiums, terrace floors | AS 4654.1 compliance, early ponding water resistance, won't re-emulsify in permanently wet conditions. | Waterproofers, Builders |
| Roofs to be covered with screeds and toppings | Withstands permanently wet conditions without re-emulsification, protecting structural elements beneath. | Waterproofers, Builders |
| General structural waterproofing for commercial, industrial, residential | High flexibility (>300% Class III elongation), robust adhesion, fungi and algae resistance. | Waterproofers, Builders |
Ensure all surfaces are clean, dry, and structurally sound. Remove laitance, contaminants, and unstable material.
Prime with Gripset GP Primer at 1L/8–10m².
Prime with Gripset OP Primer at 1L/12m².
Apply Gripset P39 by brush or roller in coats perpendicular to each other.
Apply 2 coats at 1.5L/m² total to achieve 1mm dry film.
Apply 3 coats at 2L/m² total for a 1.2mm dry film.
This material is classified as non-hazardous chemical, non-dangerous goods.
Wear safety shoes, overalls, gloves (nitrile rubber recommended for intermittent contact), and safety glasses.
Natural ventilation should be adequate under normal use conditions.
Store in original unopened packaging for up to 12 months. Keep in a cool, dry, well-ventilated place, out of direct sunlight, and off cold floors. Avoid freezing conditions. Dispose of material and container according to local regulations.
Proper surface preparation and priming are critical for Gripset P39 to achieve its documented performance and prevent adhesion failure.
Surface prep: Surfaces must be clean, sound, smooth, and dry, free from loose material, dust, oil, and existing coatings. Mechanically remove unsound layers. Fill all defects, voids, and non-structural cracks. Concrete requires 28 days cure, cement render/screeds 7 days cure.
Primer: Required. Select from Gripset GP Primer (porous), Gripset OP Primer (non-porous), Xpress Primer H2O Plus (green/damp with residual moisture), or Gripset E60 (damp, rising damp, high residual moisture >80%RH or 5% MC).
Surface prep: Ensure surfaces are clean, sound, smooth, and dry. Remove all contaminants that might compromise adhesion. Building surfaces must be fit for purpose and installed to manufacturer recommendations.
Primer: Required. Select from Gripset GP Primer (porous), Gripset OP Primer (non-porous), Xpress Primer H2O Plus (green/damp with residual moisture), or Gripset E60 (damp, rising damp, high residual moisture >80%RH or 5% MC).
| Property | Value |
|---|---|
| Form | Viscous Liquid |
| Colour | Light grey |
| Specific Gravity | 1.3 kg/litre |
| Elongation Classification (AS1145.3) | >300% Class III |
| Tensile Strength (AS1145.3) | >3 MPa |
| Water Absorption (AS 3558.1) | 4% |
| Water Vapour Transmission (ASTM E96 Desiccant method) | 1.6 g/m²/24 hours |
| Compliance to AS4858 | PASS |
| Compliance to AS 4654.1 | PASS |
| Minimum Application Temperature | 5 °C |
| Maximum Application Temperature | 30 °C |
| Recoat Time | 2-4 hours |
| Tiling/Toppings Time | 24-48 hours |
| Full Cure/Flood Test Time | 72 hours |
| Shelf Life | 12 months |
| Packaging | 15 Litre pails |
Here are some common examples on where Gripset P39 Membrane used by our customers.
