Precision Decking for Tight Spaces: Thermo Bamboo and Aluminium Create a Premium Low-Profile Terrace in London

In November 2024, a London homeowner faced a common rooftop design challenge — how to create a stylish, durable decking area over a roof terrace with just 60mm of build-up space. The project required a solution that could navigate around two existing rooflights without compromising on strength, stability, or aesthetic quality.

Wallbarn’s aluminium and Thermo Bamboo decking system offered the perfect answer, combining low-profile engineering with premium, sustainable materials to deliver a high-end result within a restricted space.

Solving the Height Restriction Challenge

Traditional timber decking substructures were not an option due to the extremely limited height available. Instead, the design called for Wallbarn’s low Box Rail aluminium joist, just 15mm in height, providing exceptional rigidity without sacrificing clearance.

These rails were mounted onto Mega Balance self-levelling pedestals, enabling precise adjustment and alignment across the roof surface. The system’s simplicity meant it could be installed quickly and efficiently, even by a DIY installer, ensuring minimal disruption and a smooth build process.

A Refined, Sustainable Decking Material

The surface finish was created using Thermo Bamboo decking boards, selected for their premium appearance, sustainability, and long-term durability. Manufactured by compressing steamed bamboo fibres under high pressure, the boards form a dense, ultra-hard surface that is more stable and rot-resistant than many tropical hardwoods.

Key performance characteristics include:

• Class Bfl-s1 fire rating, meeting strict building standards

• Biological Class 1 “Very Durable” classification

• Excellent resistance to warping, movement, and splitting

• Minimal maintenance requirements, ideal for long-term use

In addition to their technical advantages, Thermo Bamboo boards are a sustainable alternative to traditional hardwoods. Bamboo is one of the fastest-growing renewable materials in construction, and the thermo-treatment process enhances its strength naturally — without the need for harsh chemicals or kiln drying.

Premium Finish and Practical Design

The completed 42m² terrace now features a warm, natural surface that enhances the character of the property. The rich brown tone of the bamboo boards complements the architecture and will gracefully weather to a silver-grey patina over time.

The deck sits perfectly flush with the rooflights, creating a seamless, functional space that feels both luxurious and practical. With its clean lines, lightweight structure, and long-lasting materials, the system demonstrates how careful detailing and precision engineering can overcome even the most challenging spatial constraints.

A Showcase of Smart Design

This project is a standout example of how Wallbarn’s low-profile decking systems can transform restricted roof areas into elegant, usable outdoor spaces. By combining Thermo Bamboo boards with an aluminium substructure, the result is a terrace that balances strength, sustainability, and visual appeal — proving that even small spaces can deliver big design impact.