Suitable for:

• Intensive green roofs: Creates a finish for lawns and intensive specialist planting.
• Semi-intensive green roofs.
• Extensive green roofs and bio-diverse roofs: Designed to be self-sufficient and low maintenance, creating a natural habitat supporting birds, insects and invertebrates.
• Biosolar roofs.
• Blue roofs: Reduces and controls the peak rate of storm water discharge, and is engineered to attenuate water at roof level to alleviate the risk of flood at ground level.

The Attenu8® System can be used in a range of areas dependent on project requirements, and can be built onto a range of different roof types.

It functions as a blue roof solution that temporarily stores and attenuates stormwater runoff, preventing downstream flooding while integrating seamlessly with green or bio-diverse roof finishes.

Adheres to the GRO Code of Practice for Green Roofs.

Features and benefits:

• Allows independent design of underlying roof drainage to meet BS EN 12056:3 2000 without conflict, guaranteeing the roof drains at engineered rates.
• Eliminates negative thermal performance from water cooling in inverted roofs, reducing insulation thickness and costs under BS 6229:2018 guidelines, while saving on build-up heights.
• Mitigates flotation risk in inverted build-ups without extra ballast, enabling lower structural design weights and lower costs.
• Works effectively with substrates laid to falls without reducing storage volumes, aligning with industry standards and insurer preferences (e.g., NHBC, Premier Guarantee, LABC) for reduced risk, and enabling retrofits on existing sloped roofs.
• Provides additional protection via a secondary fully sealed membrane layer, reducing risk for critical structures like data centres or healthcare buildings.
• Handles exceedance events by overflowing into external drainage as per BS EN 12056:3 calculations, avoiding incorrect flow rate assumptions in external systems.
• Offers a fully joined-up insulated waterproofing and attenuation specification, achieving compliance for thermal, waterproofing, SuDS, living green roofs, and bio-solar photovoltaic systems, leading to 'right first time' designs and avoiding interface issues.
• Aligns drainage and thermal calculations for cost-effective solutions within available build heights, preventing costly upgrades like vacuum insulation.
• Provides single-point specification, design responsibility, and insured guarantee covering all elements, simplifying chains of responsibility and avoiding disputes.
• Can be installed at any time of the year.
• Achieves half 'drain-down' time, meeting hydraulic calculations and planning conditions.
• Enables system re-use, aligning with London Plan ambitions.
• Manages silt and debris effectively.
• Easy to maintain per GRO and Ciria C817 guidance.
• Life expectancy matches the waterproofing and building design life.
• Contributes to BREEAM credits when combined with rainwater harvesting.
• Reduces need for below-ground attenuation tanks, saving costs and basement space in urban environments.

Consists of:

• Waterproofing.
• Thermal insulation.
• Water flow reducing layer.
• Overflow control layer.
• Water barrier layer.
• Joint tape.
• Protection layer.
• Attenuation layer.
• Attenuation filtration layer.
• Moisture control layer.
• Geotextile layer.
• Growing medium.
• Vegetation.
• Outlets.
• Flow rate control.
• Overflow control.
• Access chambers.
• Fire breaks.
• Edge retaining profile.
• Slope retaining profile.
• Accessories.