About Us

James McLean
Founder and Managing Director, Merx Pacific Ltd – Silca System

James brings a lifetime in construction, raised in a family of traditional carpentry, studied architecture, qualified builder, and is a Licensed Building Practitioner (LBP).

With over 26 years’ on-site experience across all industry sectors, he brings a practical, buildability-focused perspective to product and systems development. His focus at Merx Pacific is on delivering construction systems aligned with smarter material use and more efficient building methods.

Outside of work, he enjoys family life, fishing and time outdoors.

The Business Behind Silca System

Silca System is operated by Merx Pacific Ltd, a New Zealand-owned company focused on introducing practical, performance-driven building systems to the local market.

Our role is not simply distribution. We work closely with builders, architects, QS and suppliers to ensure Silca System is specified, cost-engineered and installed correctly across residential and commercial projects.

History

Silca Grate is the original structural tile support grid, developed by Silca System, now StoneDeks, Ohio, USA, in 2003. It has a proven international track record spanning more than 23 years, including over 13 years of supply across New Zealand and Australia. Today, Merx Pacific manufactures Silca Grates in New Zealand exclusively for the Australasian and European markets, using recycled materials and continuing the technical development of the original system.

Our Approach

We prioritise product integrity, compliance pathway and buildability. Silca System provides a rigid structural support surface for tiles and pavers on timber joist structure for above ground or on adjustable pedestals for above membrane, without reliance on elevated concrete slabs or traditional timber decking finishes.

Clear documentation, compliance alignment and practical installation guidance are central to how we operate.

Looking Forward

The construction industry continues shifting toward smarter structural methods and environmentally responsible material selection. Silca System enables permeable elevated deck structures that are durable, serviceable and long-lasting.

Our objective is straightforward: deliver a system that performs technically, installs efficiently and stands the test of time.

Environmental

Silca System and Merx Pacific: Committed to Sustainability

Manufactured with environmental consciousness at its core, the Silca System is more than just a structural support solution—it’s a commitment to building a greener future.


The Silca System grates and connectors are manuafctured entirely from recycled plastics, reducing the need for virgin materials and helping to divert waste from landfills.

Our Contribution to Sustainability

To date we have recycled an impressive:

0

kg of recycled plastic

By transforming waste plastic into durable, high-quality construction materials, we help reduce landfill and support a more sustainable future.

Supporting Natural Water Cycles

Traditional paved patios often trap rainwater causing runoff, erosion and strain on stormwater systems.
With the Silca System rainwater can:

  • Replenish the earth below nourishing soil and vegetation
  • Prevent waterlogging by promoting proper drainage
  • Reduce strain on urban drainage infrastructure

Key Benefits When Specifcying Silca System 

Design & Site Adaptability

Silca System accommodates a range of elevated paving applications, including decks, balconies, terraces and external public spaces. The interlocking grate format can be configured across timber joist and aluminium framing systems, with individual grates cut on site to suit perimeter details and structural obstructions.

 

Structural Performance & Load Distribution

The interconnected Silca Grates create a continuous, rigid support surface beneath tiles, natural stone and pavers. Mechanically fixed to the supporting structure, the system distributes applied loads across the substructure, providing a stable platform for external paving finishes.

 

Substructure Ventilation & Integrated Drainage

The open-cell grate construction allows water to drain through the paved surface and provides airflow beneath the finished level. This supports drainage, ventilation and drying of the underlying structure. Elevated configurations can also accommodate level-entry thresholds where project design and structural requirements permit.

Compliance & Fire Mitigation

Silca System supports compliance with relevant New Zealand Building Code requirements, including B1/VM1 (Structure), B2 (Durability) and E2/AS1 (External Moisture). Structural loading is assessed in accordance with AS/NZS 1170.1. System performance is considered against the supporting substructure, spans, loading requirements and project-specific design.

 

Material Sustainability & Proven Performance

Silca Grates are manufactured in New Zealand using recycled PCABS plastic with UV stabilisation. The use of recycled material supports the reuse of existing plastic resources while local manufacturing supports domestic supply and product availability.

 

Installation & Cost Efficiency

Silca Grates provide a modular support layer that can be mechanically fixed to timber joists or incorporated into aluminium framing and pedestal assemblies. The system can be integrated into different construction methodologies without requiring a conventional concrete substrate beneath the finished paving surface.

Let's discuss your project

Early-stage Design Assistance    -    System Selection    -    Procurement    -    Support

Contact

Auckland, New Zealand