Delivering a Seamless Pitch-to-Flat Roof Upgrade for School

WHEN SYNERGY Construction needed a reliable roofing solution for Parmiter’s School in Watford, they returned to Garland UK, this time to transform a failing metal pitch roof into a high-performance flat roofing system.

Daniel Sandell, Garland UK Technical Manager

The project, funded through the Condition Improvement Fund (CIF), required a solution that improved durability, safety, and energy efficiency while keeping the school fully operational. Garland UK Technical Manager, Daniel Sandell, led the design and oversaw the project installation, ensuring smooth delivery and regulatory compliance.

Designed For Performance

The 2,742m² roofing area presented serious structural and environmental challenges. The metal pitch roofs suffered severe water damage, with framing detaching from joists, creating wind uplift risks and structural instability.

Thermal inefficiency was another issue. The existing roof had a U-value of 3.36, leading to excessive energy waste and high operational costs. Upgrading insulation was crucial to meeting modern energy efficiency standards.

Outdated Georgian-wired roof lights and asbestos-containing materials in the perimeter fascia introduced additional safety concerns. Addressing these risks without disrupting school operations was critical.

Before installation

Phased Installation, Minimal Disruption

Garland UK worked closely with Synergy Construction and approved contractor, Accurate Roofing, to execute a phased approach. This ensured seamless project management, uninterrupted school operations, and an efficient workflow for contractors on site.

The existing chipboard and woodwool deck was overlaid with 18mm marine-grade ply. The overlay method in Garland’s design specification ensured the new plywood decking was applied through the chipboard and into the joist, enabling Accurate Roofing to install the system quickly while keeping the building dry from the elements.

By retaining the existing structure rather than removing it entirely, this solution minimises waste and disruption. A self-adhesive vapour control layer was then added to reduce fire risks, a crucial safety measure given the composition of the original deck materials. To further enhance the roof’s performance, a tapered insulation system was installed to improve energy efficiency, followed by a base sheet to bond with the final layer.

The final layer consisted of Garland’s BBA-certified StressPly Flex Plus torch-on cap sheet, renowned for its exceptional durability and waterproofing capabilities. This system was backed by a 25 year Single-Point Guarantee, providing long-term assurance for the school.

To enhance daylight and eliminate safety risks, outdated Georgian-wired roof lights were replaced with modern triple-skinned polycarbonate units, improving natural light distribution within the building.

After installation

Backed by Garland

The transformation significantly improved the roof’s thermal performance, bringing the U-value down to 0.18. This will reduce energy costs, improve environmental impact, and ensure long-term sustainability. By retaining and reinforcing the existing structure, this project avoided over 70 tonnes of waste to landfill, aligning with Parmiter’s School’s sustainability goals while streamlining installation for the roofing team.

School Business Manager, Jon Whitehouse, praised the project, stating: “The transformation of our school’s roof has been remarkable. Garland UK’s thoughtful technical approach and smooth project management tackled our long-standing waterproofing and energy efficiency issues while keeping disruptions to our operations minimal. Their focus on safety, sustainability, and long-term performance shines through in every detail of the project. With their tailored solutions and dedicated support, Garland has significantly enhanced the safety and environmental standards of our facility, delivering a durable and future-ready roofing system.”

With Garland UK’s 25-year Single-Point Guarantee and PartnerCare service, this project demonstrates how contractors and specifiers can rely on Garland to deliver opportunities, technical expertise, and lasting solutions.

For more information, visit the Garland UK website.

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