Repairing concrete or covering joiner plates on tilt-slab and pre-cast panels often demands precise, high-build solutions. Traditional heavy mortars can require extensive formwork, risk shrinkage, and may lack critical fire ratings. Penapatch Panel LW delivers a lightweight, non-structural alternative, simplifying these complex repairs. It allows high-build applications up to 100mm overhead and 50mm vertically without formwork, while delivering a 4-hour fire rating, making panel repairs both efficient and compliant.

Why this product exists

Penapatch Panel LW was formulated to address the specific challenges of non-structural, high-build repairs on vertical and overhead concrete and masonry, particularly within tilt-slab and pre-cast construction. Unlike conventional heavy structural repair mortars that often require extensive formwork and may lack specific fire ratings, this product combines fine fillers, lightweight aggregates, and polymers with cement to create a mortar that allows for single-application builds up to 100mm overhead, eliminating the need for formwork. This delivers a reliable, shrinkage-compensated repair that can be sanded to a smooth, paint-ready finish. Its integral 4-hour fire rating at 35mm thickness also makes it suitable for critical fire-resistant panel applications.

The numbers that matter

Penapatch Panel LW achieves a 4-hour fire rating to AS1530.4 when applied at just 35mm thick. This ensures compliance for fire-rated panel systems without excessive material build-up. Its lightweight formulation yields 15 litres per 10kg bag, allowing repairs up to 100mm overhead and 50mm on vertical surfaces in a single pass without sag. The 28-day compressive strength of 20 MPa confirms its robustness for non-structural applications, providing lasting durability while its shrinkage-compensated properties maintain dimensional stability over time, resisting reflective cracking in the repair itself.

What it's like to use

This mortar requires only the addition of water, mixing to a smooth, soft consistency with a high-shear drill mixer. With an initial set time of 3 hours and a final set of 5 hours at 20°C, it provides a workable window for shaping and finishing. Apply using a trowel or gloved hand, ensuring thorough compaction. For a smooth, paint-ready surface, finish with a steel trowel without overworking. Clean all equipment with water immediately after use. For applications in warm, windy, or exposed conditions, consider using RLA Rendergrip A as a curing agent to prevent premature drying.

Where this product excels

  • Tilt-slab and Pre-cast Panel Repair: Ideal for patching damaged sections and, critically, for covering metal joiner plates where its fire rating and high-build capability without formwork simplify complex panel rehabilitation.
  • Vertical Concrete and Masonry Repair: Allows for single-pass repairs up to 50mm on vertical surfaces, providing a lightweight yet durable solution for spalled concrete or general deterioration.
  • Overhead Concrete Repair (Soffits): Its lightweight composition supports builds up to 100mm on overhead surfaces, enabling efficient and formwork-free repairs of soffits and ceilings.
  • Fire-Rated Panel Systems: Where fire resistance is paramount, the 4-hour fire rating at 35mm thickness makes it a go-to for ensuring the integrity of fire-rated panel assemblies.

How it fits in a real system

In specific concrete repair sequences, Penapatch Panel LW acts as a filler after initial surface preparation and priming. For instance, in systems documented as Megapoxy H → Penapatch LW, a heavy-duty epoxy primer like Megapoxy H Epoxy Resin is applied first to prepare the substrate, followed by Penapatch Panel LW to build up the damaged section. This sequence ensures optimal bond and performance, even in areas that may later be membrane-covered or tiled, provided the application is vertical or overhead.

Choose this when

  • When you need to repair damaged concrete or masonry on vertical or overhead surfaces and require a high-build, non-structural solution.
  • When the job involves covering metal joiner plates in tilt-up or pre-cast panels where a fire rating is essential.
  • When you require a lightweight repair mortar that can achieve up to 100mm build overhead or 50mm vertically in a single application without formwork.
  • When the final finish needs to be smooth and paint-ready, compatible with protective or decorative coatings.
  • When negligible shrinkage and long-term dimensional stability are critical to prevent future cracking in the repair.

Don't use this when

  • Not for structural repairs: This product is non-structural; do not use where load-bearing capacity or structural integrity is required. Refer to RLA Penapatch HB50 for structural concrete repair.
  • Not for horizontal surfaces: Specifically designed for vertical and overhead applications; avoid using on floors, driveways, or other horizontal ground repairs.
  • Not for traffic areas: It is not designed or recommended for pedestrian or vehicle traffic.
  • Not for active movement joints: While shrinkage-compensated, it will not bridge active cracks or movement joints in the substrate; reflective cracking will occur.

Penapatch Panel LW achieves a 4-hour fire rating to Australian Standard AS1530.4 when applied at a minimum thickness of 35mm. This certification is crucial for maintaining the fire integrity of structural elements and panel systems in construction.