For patching repairs and covering metal joining plates in tilt-up or pre-cast panels, Penapatch Panel LW Mortar provides a lightweight, shrinkage-compensated option that eliminates the need for formwork. It is formulated to rebuild damaged concrete, masonry, steel, and rebar surfaces, achieving a four-hour fire rating to AS1530.4 when applied at a thickness of 35mm.
Penapatch Panel LW Mortar combines lightweight aggregates, select cements, and polymers to allow deep vertical and overhead build-ups without sagging. The polymer-modified formula is shrinkage-compensated to ensure long-term dimensional stability and prevent cracking at the bond line. It adheres directly to concrete, masonry, steel, and rebar, and can be sanded to a smooth finish compatible with conventional decorative coatings and the RLA range of protective coatings.
Clean the substrate to remove all oil, grease, paint, and laitance. Remove cracked or weakened concrete, and clean any exposed steel or rebar to a bright condition to remove corrosion. Prime cleaned steel reinforcement with RLA Zinc Primer and allow it to dry completely before applying the mortar.
Pre-soak concrete and masonry surfaces with clean water, ensuring no standing water remains. For highly porous surfaces, apply RLA Rendergrip A before pre-soaking to prevent the mortar from flash drying and losing its workability.
To mix, add the powder slowly into 3.1 to 3.6 litres of clean water per 10kg bag while mixing with a high-shear spiral paddle on slow to medium speed. Mix until a smooth, soft consistency is achieved. Apply by trowel or gloved hand, compacting the mortar firmly into the substrate and around reinforcement. Finish with a steel trowel without overworking the surface. In warm, windy, or exposed conditions, apply RLA Rendergrip A as a curing agent after the final trowel to prevent premature drying.
No, Penapatch Panel LW is specifically a non-structural repair mortar. It is not designed for load-bearing applications or as a structural repair mortar.
Penapatch Panel LW achieves a four-hour fire rating to AS1530.4. This rating applies when the mortar is installed at a minimum thickness of 35mm.
No, this product is not recommended for pedestrian or vehicle traffic. It is designed for vertical and overhead applications on concrete and pre-cast panels, not for floors.
For vertical applications, Penapatch Panel LW can be applied up to 50mm thick. For overhead soffits, it allows builds up to 100mm in a single application.
| Application | Key benefit | Primary trades |
|---|---|---|
| Covering metal joining plates in tilt-up/pre-cast panels | Achieves a 4-hour fire rating (AS1530.4 at 35mm) while creating a smooth, paintable surface. | Pre-cast erectors, commercial builders |
| High-build vertical concrete repairs (up to 50mm) | Allows significant build in one application with good adhesion and minimal sag, eliminating the need for formwork. | Concrete repairers, civil contractors |
| Overhead concrete soffit repairs (up to 100mm) | Achieves high-build repairs in a single pass with negligible shrinkage, reducing labour and material steps. | Specialist repair contractors, renderers |
| General non-structural concrete damage repair | Provides shrinkage-compensated stability and a fast-drying, smooth finish ready for coating or rendering. | Commercial renovators, maintenance teams |
Mechanically prepare to a sound surface; saw-cut repair edges and achieve ≥5 mm minimum depth. Pre-soak, then remove all free water.
Scabble/water-blast to remove laitance and contaminants; SSD before placement.
Clean to bright metal; prime with a zinc-rich primer and allow to dry fully.
Add powder to water while mixing with a spiral paddle to a smooth, soft mortar. Typical water per 10 kg: ~3.1–3.6 L (nominal 3.5 L).
Use room-temperature water. Mix until lump-free; do not over-water.
Use chilled water above 30–35 °C ambient; warm water below 5–10 °C to maintain workability.
Compact mortar into the cavity and around reinforcement. Build to the required thickness (min 5 mm; max 50 mm vertical, 100 mm overhead) and steel-trowel to a smooth finish.
Place in one lift up to 50 mm where practical; avoid feather-edges over large areas.
Build up to 100 mm with thorough compaction to manage sag; support may be unnecessary due to lightweight, cohesive mix.
Protect from rapid drying (sun/wind) and rain/water for ≥24 h. Implement appropriate curing, then overcoat with compatible systems after adequate drying.
Apply a curing aid immediately after finishing to control moisture loss and minimise shrinkage.
Confirm dryness and follow the coating manufacturer’s over-plaster/over-render recoat times.
DANGER: Causes skin irritation. May cause an allergic skin reaction. Causes serious eye damage. May cause respiratory irritation. May cause damage to organs through prolonged or repeated exposure. May cause cancer by inhalation.
Wear protective gloves, protective clothing, safety glasses with side shields or chemical goggles, and face protection. Use a Type P filter respirator of sufficient capacity if dust becomes airborne.
Use only outdoors or in a well-ventilated area. Ensure process controls, enclosure, or isolation of emission sources are used to minimise worker exposure.
Store in original, securely sealed containers in a cool, dry, well-ventilated area. Keep off cold floors and out of direct sunlight. Store away from incompatible materials. Dispose of unused product or contaminated wash water responsibly, consulting local regulations; do not discharge into sewers or waterways.
Proper surface preparation and priming are critical for adhesion and the long-term performance of any cementitious repair mortar.
Surface prep: Surfaces must be free of oil, grease, dust, plaster, paint, and other bond-inhibiting contaminants. Remove all cracked or weakened concrete to create a solid foundation. Scabble or water blast to remove laitance and provide a mechanical key. Saw-cut repair edges to ensure a minimum 5mm depth. New concrete substrates require a minimum of 21 days curing before application.
Primer: Optional. Pre-soak surfaces with clean water; ensure no free-standing water remains before application. For highly porous surfaces, apply RLA RENDERGRIP A before pre-soaking to control flash drying and maintain workability.
Surface prep: Break out concrete to expose all rust-affected steel reinforcement. Remove all loose scale and corrosion deposits. Clean steel to a bright condition, ideally by grit blasting.
Primer: Required. Prime all cleaned steel with RLA ZINC PRIMER. Allow the primer to dry completely before applying Penapatch Panel LW.
| Property | Value |
|---|---|
| Colour | Light Grey Powder |
| Fresh Wet Density | 900 kg/m³ |
| Shelf life | 12 months |
| Packaging | 10kg Poly-lined Bags |
| Application Temperature | 5ºC - 35ºC |
| Coverage | 1.85 kg/m²/mm |
| Water per 10kg bag | 3.1 - 3.6 litres |
| Yield per bag | 15 litres |
| Flexural Strength 1 day | 3.0 MPa (at 20ºC) |
| Flexural Strength 7 days | 5.0 MPa (at 20ºC) |
| Flexural Strength 28 days | 7.1 MPa (at 20ºC) |
| Compressive Strength 1 day | 4.0 MPa (at 20ºC & 50% RH) |
| Compressive Strength 7 days | 18 MPa (at 20ºC & 50% RH) |
| Compressive Strength 28 days | 20 MPa (at 20ºC & 50% RH) |
| Initial Setting Time | 3 hours (at 20°C) |
| Final Setting Time | 5 hours (at 20°C) |
| Young's Modulus | approx. 26 GPa |
| Coefficient of Thermal Expansion | 7-10 x 10⁻⁶ mm/ºC |
| Vertical Application Thickness Minimum | 5mm |
| Vertical Application Thickness Maximum | 50mm |
| Overhead Soffits Thickness Minimum | 5mm |
| Overhead Soffits Thickness Maximum | 100mm |
| Fire Rating | 4 hours to AS1530.4 (at 35mm thickness) |
Here are some common examples on where RLA Penapatch Panel LW Mortar used by our customers.
