LF Replacement Windows’ LEKA Orangery Flat Roof with Lantern combines contemporary style with outstanding thermal performance, creating a bright, elegant and comfortable living space for any home. Designed to deliver the luxurious appearance of a traditional orangery with the sleek lines of a modern flat roof system, the stunning central glass lantern floods your room with natural light while maintaining exceptional insulation and energy efficiency.

Manufactured using advanced lightweight materials and precision engineering, the LEKA Orangery Roof system is designed to transform conservatories, extensions, and new living spaces into usable rooms all year round.

How the LEKA Orangery Roof System is Constructed

Step 1 – LEKA GRP Rafters
The installation begins with advanced Glass Reinforced Plastic (GRP) rafters being fitted onto existing or new orangery window frames, including a GRP structural upstand. GRP offers a higher tensile strength than steel whilst eliminating many common issues associated with traditional materials. Unlike timber, it is not prone to woodworm, rot, moisture absorption or expansion, and unlike aluminium or steel, it prevents condensation and thermal bridging. This forms the foundation of the roof’s superior insulation performance.

Step 2 – PIR Insulation
High-grade PIR insulation sheets are carefully fitted within the roof structure, significantly enhancing thermal efficiency. PIR insulation is one of the UK’s leading insulation products and is BBA approved, helping to keep your orangery warm during winter and cooler throughout summer. ECO options featuring EPS polystyrene insulation are also available.

Step 3 – LEKA External Boards
Strong, insulated and load-bearing LEKA external boards are then installed. These engineered boards provide a lightweight alternative to plywood or OSB while delivering exceptional structural strength. They are 100% waterproof, weatherproof and thermally efficient, helping to reduce the number of roofing bars required for a cleaner appearance. A breathable membrane is then applied for additional weather protection.

Step 4 – Outer Weatherproof Coating
A premium outer weatherproof coating is applied using either EPDM rubber or fibreglass, creating a sleek, durable and fully watertight finish. This ensures your orangery remains protected from the elements and comfortable throughout the year.

Step 5 – Glass Lantern Installation
The elegant glass lantern is then constructed onsite in accordance with manufacturer guidelines. The lantern becomes the centrepiece of the orangery, allowing natural light to pour into the room while adding a luxurious architectural feature that enhances both modern and traditional homes.

Step 6 – Fascias and Guttering
UPVC fascias and cappit boards are fitted to complete the roof edges, with optional guttering installed for efficient rainwater drainage and a neat, professional finish.

Step 7 – Internal LEKA Boards
Internally, lightweight waterproof LEKA boards are installed beneath the GRP rafters. These innovative boards weigh only one third of traditional plasterboard whilst offering excellent thermal properties. They are designed to accept a traditional plaster skim finish ready for decoration. Alternative options such as standard plasterboard or LEKA Ecotech insulated plasterboards are also available, achieving impressive U-values from as low as 0.10.

Step 8 – Internal Plaster Finish
Finally, the interior is completed with a high-quality traditional skim plaster finish, creating a smooth modern ceiling ready for painting. Low-energy spotlights can also be installed to complete the perfect orangery living space.

The LEKA Orangery Flat Roof with Lantern from LF Replacement Windows offers the perfect combination of style, strength, insulation and natural light — creating a beautiful new living area that can be enjoyed comfortably throughout every season.