Video
Cathedral Fig Tree FRP Boardwalk
Overview
This Tech Talk Tuesday session presents a case study on the Cathedral Fig Tree boardwalk, a NatureTREAD FRP boardwalk project delivered by Treadwell for a sensitive rainforest tourism location in Far North Queensland. The Cathedral Fig Tree is located in Danbulla National Park and State Forest in the Atherton Tablelands, and Queensland Parks describes the site as a short 300 metre return Grade 2 walk featuring the tree’s cathedral-like root formation.
The project required a safe elevated visitor access structure that would protect the tree’s sensitive root system while allowing tourists to experience the site without causing long-term environmental damage. The transcript explains that the boardwalk was installed in 2017, designed for a 5 kPa uniformly distributed load and a 4.5 kN point load, with most sections around 1800 mm wide and suitable for wheelchair access.
Treadwell’s scope was to develop and supply the structure, including engineering and shop drawings, with installation completed by Dorson’s Engineering in Cairns. The completed system used FRP beams, square hollow sections, FRP grating, FRP brackets, stainless steel 316 bolts, timber kick rails, timber handrail elements and powder-coated infills, showing how FRP can be integrated into a hybrid boardwalk design for both performance and aesthetics.
Key Features
Low-impact access for a sensitive rainforest site
The boardwalk was designed to keep visitors away from the Cathedral Fig Tree’s sensitive root system while still allowing safe viewing access around the tree. The transcript explains that high visitor volume on the original walking path created a long-term risk to the tree’s health, making an elevated boardwalk solution necessary.
Lightweight structure for manual installation
FRP’s lightweight nature allowed components to be moved and installed using manpower, hand tools and battery tools. This helped reduce the need for heavy machinery in a rainforest environment where site disturbance needed to be minimised.
No hot works required on site
The boardwalk was assembled with bolted connections, avoiding welding and hot works. This is especially useful in public infrastructure and environmental projects where installation needs to be controlled, clean and low impact.
Surface-mounted footing approach
The project used concrete pads or plinths that sat on the ground, helping avoid the root disturbance that could have occurred with driven piles or screw piles. This was a key solution for soil and root conservation around the fig tree.
Corrosion, rust and rot resistance
FRP was selected because it does not corrode, rust or rot in the way steel and timber can. This is important in a damp rainforest setting where timber may require ongoing maintenance and steel may face long-term corrosion risk.
Anti-slip FRP grating for visitor safety
Treadwell’s FRP grating was used as the decking component. The session notes that the grating provides an anti-slip finish with P5 and R13 slip ratings, helping improve visitor safety in wet rainforest conditions.
Long design life with reduced maintenance
The boardwalk was described as having a case proven and issued a 50-year design life. Eight years after installation, the structure was reported to be looking better than ever, with vegetation growing around it and only minor inspection requirements for bolted connections.
Modular and demountable structure
Because the structure uses bolted connections, it can be demodularised if required. This means sections can be removed or replaced if a branch falls or if localised damage occurs, rather than replacing the entire structure.
Hybrid design for natural aesthetics
The project combined FRP structural elements with timber kick rails, timber handrail elements and powder-coated infills. This allowed the boardwalk to benefit from FRP durability while maintaining an appearance suitable for a rainforest tourism setting.
Proven NatureTREAD boardwalk experience
NatureTREAD states that the Cathedral Fig Tree Rainforest Boardwalk uses NatureTREAD FRP to create a safe, corrosion-resistant, low-impact path around the base of the tree and its buttress roots.
Applications
Rainforest boardwalks and environmentally sensitive trails
The Cathedral Fig Tree project demonstrates how FRP boardwalks can be used in rainforest environments where the goal is to protect soil, roots and vegetation while still allowing public access.
Tourism infrastructure in national parks
The project supports safe visitor movement around an iconic natural attraction while reducing the environmental impact of repeated foot traffic. The Queensland Parks listing describes the Cathedral Fig Tree walk as a short visitor journey within Danbulla National Park and State Forest, reinforcing its tourism and public access role.
Wheelchair accessible boardwalk design
With most of the boardwalk around 1800 mm wide and designed for suitable wheelchair access, the project is relevant to public infrastructure where access, circulation space and visitor inclusivity are important design goals.
Low-level boardwalks on concrete plinths
The Cathedral Fig Tree boardwalk used concrete pads or plinths placed on the ground rather than driven or screw pile foundations. This approach is useful where root protection, soil conservation or reduced excavation is a priority.
FRP structures in humid and damp environments
Rainforest settings can create long-term challenges for timber and steel due to moisture, rot and corrosion. FRP provides a low-maintenance alternative for boardwalk structures exposed to damp conditions.
Public viewing platforms
The project included two photo and viewing platforms integrated into the boardwalk design, showing how FRP systems can support tourism viewing points, pause areas and wider access nodes within a boardwalk route.
Hybrid boardwalk systems
The use of FRP structural profiles with timber and powder-coated elements shows how Treadwell can support hybrid designs where durability, environmental performance and visual integration are all important.
Projects requiring off-site design and shop drawings
Treadwell provided engineering and shop drawings to the installation contractor, demonstrating how FRP boardwalk systems can be developed, documented and supplied for local contractor installation.
Modular public infrastructure
The bolted FRP boardwalk format allows sections to be demodulised if required for damage repair, future maintenance or environmental management. This is useful for public infrastructure assets located in areas where tree falls, weather events or changing site conditions may occur.
Other NatureTREAD boardwalk projects
The session briefly references additional NatureTREAD boardwalk projects, including Arno Bay Boardwalk, Whitsunday Island, Witton Bluff Boardwalk, Burleigh Heads / Tallebudgera Creek, and the Beach to Beach or Dunbogan Boardwalk. These examples show that the same FRP boardwalk approach can be adapted to sand dunes, mangroves, coastal access, elevated structures and screw pile supported systems.
Key Moments
- 01:25:00 👋 Ryder Morton introduces the webinar on the Cathedral Fig Tree Boardwalk as Business Solutions Manager for Treadwell's Nature Tread space.
- 01:51:00 🏗️ Nature Tread specialises in FRP products for public infrastructure like boardwalks, pedestrian bridges, and coastal access structures.
- 02:32:00 🧪 FRP is fibreglass reinforced polymer: glass reinforcement provides strength/shape; isophthalic (I-series) and vinylester (V-series) resins with fire retardants and UV inhibitors suit Australian conditions.
- 03:26:00 ✅ FRP benefits include corrosion/rust resistance, no maintenance or coatings needed, no hot works permits, nonconductive, and high strength-to-weight ratio.
- 04:10:00 🌿 Boardwalks protect environmentally sensitive areas; Treadwell offers pre-engineered Brighton and Waterfall series designs.
- 04:52:00 🌳 The 500-year-old heritage-listed Cathedral Fig Tree in Dimbulah National Park (Atherton Tablelands, QLD) is ~50m tall with a 2,000m² crown and a sensitive root system.
- 05:50:00 🔧 Installed in 2017 by Dorson's using on-site FRP fabrication with hand/battery tools and bolted connections; now an elevated, root-protecting tourist access system.
- 06:32:00 📐 Design specs: 5kPa UDL + 4.5kN point load, 1.8m wide with wheelchair access and two viewing platforms.
- 07:12:00 🪵 Key FRP components: 203x203 wide flange beams (bearers), 100x10 SHS, mini-mesh grating, 76mm angles, 316 stainless bolts; hybrid timber handrails/kerbs for aesthetics.
- 08:21:00 🪨 Footings use surface concrete pads/plinths; all assembly with simple power tools and chem-set anchors.
- 09:05:00 ⚠️ Major challenges included protecting the fig tree's roots from high visitor traffic; the elevated FRP boardwalk was the solution.
- 09:33:00 🚫 Steel was unsuitable due to heavy machinery needs, welding, and future corrosion in humid rainforest; timber risked rot and high maintenance.
- 10:13:00 🪶 FRP enables lightweight, low-impact installation (two-person lifts), full modularity/demountability, and easy repairs if damaged.
- 10:53:00 🛡️ Surface concrete plinths avoid root/soil damage, unlike driven piles; FRP grating delivers P5/R13 anti-slip rating.
- 11:33:00 ⏳ Premium FRP matrix ensures no corrosion/rot with a proven 50-year design life and minimal long-term costs for Queensland Parks.
- 12:00:00 📸 Eight years post-install (2017), the boardwalk remains in excellent condition with minimal maintenance required.
- 13:08:00 📍 Other Treadwell boardwalk projects include Arno Bay (sand dunes), Whitsunday Island (mangrove span bridge), and Burleigh Heads.
- 14:56:00 💰 Approximate 2017 cost: $500–600 per m² for structural frames; footings were ~400–500mm deep surface concrete blocks.
Why Choose Treadwell ?
Treadwell’s NatureTREAD division focuses on public infrastructure projects such as boardwalks, pedestrian bridges, coastal access structures, staircases and access ramps. The Cathedral Fig Tree case study shows how that focus translates into a practical FRP solution for a sensitive tourism and conservation site.
Treadwell can support boardwalk projects with FRP product selection, engineering, shop drawings, standard boardwalk concepts and custom design input. NatureTREAD states that it offers FRP boardwalk design, engineering and installation, with standard designs such as Brighton, Cathedral and Waterfall series, along with custom designs where required.
The Cathedral Fig Tree boardwalk also shows Treadwell’s ability to balance structural performance with conservation requirements. Lightweight FRP, bolted connections, surface-mounted plinths, anti-slip grating and modular construction all helped reduce impact on the tree’s root system while providing safe, durable visitor access.
For councils, parks authorities, tourism sites and public infrastructure teams, Treadwell offers a strong combination of FRP durability, low maintenance performance, design support and practical installation thinking. The result is boardwalk infrastructure that can protect sensitive environments, improve visitor access and reduce long-term maintenance demands.
