The Sustainable Flat Roof System, powered by PolyroofGreen, transforms flat roofs into high-performing, ecologically valuable assets. Combining Polyroof's proven cold liquid-applied waterproofing with a comprehensive range of green roof, blue roof, and BioSolar options, designed and supplied in partnership with a specialist green roof installer, the system is suitable for both new build and refurbishment projects.
Polyroof's commitment to sustainability goes further than the green roof itself. Protec Evolve, one of the two waterproofing options powering this system, is independently certified carbon neutral, and Roberts Group was proud to win the Edie Net Zero Awards 2024 SME Net Zero Strategy of the Year, recognising our industry-leading approach to sustainable flat roofing.
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All PolyroofGreen systems contribute to measurable Biodiversity Net Gain, supporting planning requirements under the Environment Act 2021. Green roof vegetation attracts pollinators, supports local wildlife, and enhances urban biodiversity, helping specifiers and developers meet BNG obligations.
Green and blue roof requirements are increasingly mandated by local planning authorities. PolyroofGreen provides a fully designed, documented, and guaranteed solution that satisfies planning conditions for sustainable drainage, biodiversity, and urban greening, from initial design through to installation.
When Protec Evolve is specified as the waterproofing layer, the system benefits from independently certified carbon neutral waterproofing. Cradle-to-grave carbon emissions are fully offset using Verified Carbon Standard (VCS) carbon credits, supporting vital renewable energy projects and helping clients achieve their Net Zero goals.
The PolyroofBlue system captures, stores, and controls the release of stormwater from the roof, acting as a critical component of Sustainable Drainage Systems (SuDS). By reducing peak run-off rates and relieving pressure on drainage networks, it helps developments comply with SuDS planning requirements.
The BioSolar option combines a green roof system with a load-supported solar PV array, generating on-site renewable energy whilst simultaneously delivering biodiversity and water attenuation benefits. The green roof mass anchors the solar frames without the need for roof penetrations, and evapotranspiration from the vegetation helps cool the panels, improving solar efficiency.
The Sustainable Flat Roof System is available with multiple green roof options, including PolyroofGreen, BioSolar (green roof + solar PV), and PolyroofBlue (blue roof). All systems are designed and supplied in partnership with our specialist green roof installation partner, and can be specified over both warm and inverted insulated roof build-ups. Waterproofing is powered by Protec or Protec Evolve. For bespoke specification advice, please get in touch with our team.
An extensive green roof system utilising a pre-grown sedum mat for instant visual impact. The blanket contains 8–12 species of sedum and provides 90% vegetation coverage, year-round green finish, and excellent water attenuation. Suitable for both new build and refurbishment, and for roof pitches up to 45°.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
Instant greening, pre-grown mat provides immediate visual impact and 90% vegetation coverage.
Low maintenance, bi-annual visits recommended; designed to evolve successfully with minimal intervention.
Can reduce and delay runoff, with performance dependent on project-specific conditions.
BREEAM credits available.
Flowering season: Spring / Autumn.
Pre-grown sedum mat containing 8–12 sedum species at 20mm depth, providing immediate vegetation coverage and year-round green finish.
Specialist blended growing medium to the required depth, providing the nutritional and structural base for the vegetation layer. Depth is project-specific and dependent on the vegetation system selected.
Geo-synthetic filtration fleece, 2mm (nominal), preventing substrate migration into the drainage layer whilst allowing free water movement.
20mm drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
A highly biodiverse and visually striking green roof system utilising a pre-grown wildflower mat sown with 30+ species of wildflower and grass. Provides >90% vegetation coverage and a vibrant display of colour from Spring through Autumn. Species are specifically chosen to survive roof conditions and maximise ecological value. Suitable for new build; for new build and refurbishment up to 15° pitch.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
30+ wildflower and grass species; >90% vegetation coverage.
Instant greening with vibrant Spring/Autumn flowering.
Greater species diversity and ecological function than standard sedum systems.
Can reduce and delay runoff, with performance dependent on project-specific conditions; BREEAM credits available.
(Plug & Seeded Systems also available)
Pre-grown wildflower blanket containing 30+ species of wildflower and grass at 30mm depth, providing vibrant colour from Spring through Autumn.
Specialist blended growing medium to the required depth, providing the nutritional and structural base for the vegetation layer. Depth is project-specific and dependent on the vegetation system selected.
Geo-synthetic filtration fleece, 2mm (nominal), preventing substrate migration into the drainage layer whilst allowing free water movement.
20mm drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
A locally sourced, site-blended bio-diverse system seeded with regional bio-diverse seed mixes. Contoured to encourage habitat diversity, and finished with surface habitats of stone, rock, sand, and wood. Complies with local bio-diversity plans and assessments. Suitable for new build and refurbishment concrete decks.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
38 species of grass, herbs, wildflower, cornflower, alpines, and perennials.
Contoured substrate (100–150mm) with surface habitats to specification.
Locally sourced UK provenance seed stock.
Low maintenance, seeded and left to self-develop.
Can reduce and delay runoff, with performance dependent on project-specific conditions; BREEAM credits available.
Regional bio-diverse seed mix (grass, herbs, wildflower, cornflower, alpines, perennials) sown at 1–3g/m² over contoured bio-diverse substrate. Surface habitats of stone, rock, sand, and wood to specification.
Specialist blended growing medium to the required depth, providing the nutritional and structural base for the vegetation layer. Depth is project-specific and dependent on the vegetation system selected.
Geo-synthetic filtration fleece, 2mm (nominal), preventing substrate migration into the drainage layer whilst allowing free water movement.
20mm drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
The BioSolar system combines a green roof with a load-supported solar PV array, delivering renewable energy generation alongside biodiversity and water attenuation benefits. Load-supported solar mounting frames require no roof penetrations. Evapotranspiration from the green roof helps cool the panels, improving solar efficiency. BioSolar systems are suitable for new build only. Designed in partnership with our specialist green roof and solar partner.
Combines a wildflower seeded green roof with load-supported solar PV, providing the greatest long-term species diversity of the BioSolar options. 44 wildflower and grass species sown into bio-solar substrate over a drainage reservoir board, delivering outstanding ecological function alongside renewable energy generation. Suitable for new build only.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
44 wildflower and grass species, maximum ecological diversity.
Load-supported solar mounting, no roof penetrations required.
Can reduce and delay runoff, with performance dependent on project-specific conditions.
BREEAM credits available.
Bio-solar seed mix (44 wildflower and grass species) sown at 4g/m² into bio-solar substrate. Load-supported aluminium solar mounting frames and PV modules, no roof penetrations required.
Specialist blended growing medium to the required depth, providing the nutritional and structural base for the vegetation layer. Depth is project-specific and dependent on the vegetation system selected.
Geo-synthetic filtration fleece, 2mm (nominal), preventing substrate migration into the drainage layer whilst allowing free water movement.
20mm drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
PolyroofBLUE is an engineered blue roof solution designed to maximise the effectiveness of stormwater management by controlling the rate of water run-off from the building. When integrated with a green roof, the system captures, treats, and stores rainwater, gradually releasing it into the drainage network to relieve pressure on drainage infrastructure and satisfy SuDS planning requirements. Fully designed and backed by Professional Indemnity insurance. Suitable for new build; typically on large open commercial roof spaces. Each design is tailored to the specific development.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
Manages stormwater run-off, relieving pressure on drainage networks and satisfying SuDS planning requirements.
Can reduce and delay runoff, with performance dependent on project-specific conditions; 90% vegetation coverage when combined with sedum green roof.
BREEAM credits available.
Pre-grown sedum blanket (10–12 species) providing 90% vegetation coverage, water attenuation, and biodiversity benefits above the blue roof build-up.
Blended 90:10 crushed brick growing medium (60mm depth) providing the substrate base for the vegetation layer.
Specialist blended growing medium to the required depth, providing the nutritional and structural base for the vegetation layer. Depth is project-specific and dependent on the vegetation system selected.
Geo-synthetic filtration fleece, 2mm (nominal), preventing substrate migration into the drainage layer whilst allowing free water movement.
20mm drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Attenuation crate system installed above the waterproofing layer, providing controlled water storage and managed release into the drainage network via outlet restrictors.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
The PolyroofGREEN Modular System offers an innovative alternative to conventional loose - laid Green Roof systems. Lightweight and fast to install, the system also offers the advantage of being easy to lift for roof inspection and to lift modules at any time if required. Precultivated UK grown vegetation, containing up to 13 species specifically chosen for Extensive green roof applications. Grown on a 80 mm substrate base within a rigid recycled polypropylene modular 600mm (L) x 400mm (W) x 80mm (H) container.
The following benefits are available when Protec or Protec Evolve are utilised as the Waterproofing Layer:
Instant vegetative cover from day of install.
Trays can be lifted & reconfigured.
Trays slot together for simple installation
BREEAM credits available.
80mm Substrate with a 20mm integrated drainage and retention cell, providing controlled drainage through the build-up whilst retaining water for the vegetation layer above.
Geo-synthetic non-woven protection fleece, 3.5mm, installed immediately above the waterproofing membrane to protect the surface during installation of the green roof build-up.
Cold liquid-applied Protec or Protec Evolve waterproofing membrane, forming the fully seamless, reinforced waterproof layer of the system, installed as part of the warm or inverted roof build-up below. (Example image shows the Polyroof Warm Flat Roof System variant)
From initial project enquiry right through to completion, Polyroof will be on-hand to support you at every stage of your project’s lifecycle.
Specification → Technical Guidance → Approved Contractors → Quality Assurance → Guarantee
