Blue roofs

Roof design solutions

Proteus Waterproofing takes pride in offering comprehensive blue roof design services that encompass precise U-Value calculations, condensation risk analysis, wind uplift, and drainage calculations. We provide a range of flat and tapered insulation schemes expertly designed to meet Part B Fire regulations. Our bespoke roof design drawings and board schedules, backed by our presence on NBS Source and NBS Chorus, ensure seamless project specification support at all times.

Water Management:

Blue roofs feature specific flow restrictor outlets to meet the required water discharge rate and are engineered to efficiently drain over a specified retention period. Overflow mechanisms are incorporated into every design to avoid water ingress during extreme weather conditions, ensuring effective water management.

Proteus will design, specify, quote, deliver, install [via our network of approved installers] and provide a guarantee on a wide range of blue roofs

Reliable partners

Proteus Waterproofing ensures that a team of friendly and knowledgeable staff members are always available to answer any questions, both in our office and warehouse. This commitment translates into next-day delivery for orders placed by 11 am (subject to stock availability) and seamless facilitation of collections, ensuring your materials reach you promptly and in perfect condition.

Guarantees and warranties

We stand behind the quality of our work with comprehensive guarantees covering both labour and materials for up to 25 years, tailored to each specific project and its duration. As an additional layer of assurance, we offer the option for an independent pre-paid insurance-backed guarantee, providing you with peace of mind and confidence in your choice.

Certifications:

Our comprehensive accreditations include ISO 9001, ISO 14001, FORS Gold and Safe2Torch. All our waterproofing systems are fully BBA certified and we are NBS Specification Writing Partner. In addition, we are members of LRWA, GRO, CORC and the NFRC.

Allows independent design of underlying roof drainage to meet BS EN 12056:3 2000 without conflict, guaranteeing the roof drains at engineered rates and safeguarding clients contractually and legally under professional indemnity insurance.

• 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.

As defined by the UK's Department for Environment, Food & Rural Affairs (DEFRA), the concept of flood-ready systems encompasses purpose-designed products that prevent or mitigate flood impacts, suitable for new constructions or retrofitting in domestic, commercial, or industrial buildings. 

Attenu8® aligns strongly with this by acting as a preventative measure against urban flooding: it detains rainfall on rooftops, reducing peak runoff and alleviating pressure on downstream drainage networks, which is critical in flood-prone UK areas like London or coastal regions. For new builds, it integrates into roof designs to enhance overall property resilience, complying with Property Flood Resilience (PFR) principles that emphasise water management to minimise damage.

In retrofits, its modular, lightweight components allow easy adaptation to existing flat roofs without major structural alterations, making it feasible for older buildings. By enabling controlled discharge and full drain-down within 24 hours, it prevents overload during extreme weather events, supporting DEFRA's flood risk management strategies and contributing to national goals for sustainable urban drainage.

The system's compliance with BS EN12056:3 2000 ensures accurate engineering for worst-case scenarios, while its secondary membrane and overflow features add layers of protection against water ingress and exceedance, further bolstering flood readiness in high-risk structures.

Attenu8® Flow Restrictor

• Function: Controls the rate of water discharge.

• Role: Made from 304-grade stainless steel, it regulates runoff to as low as 0.07 l/s, preventing downstream drainage overload. Attached to outlet raising rings, it ensures precise flow management in the blue roof system.

Attenu8® Overflow Device

• Function: Manages excess water during heavy rainfall.

• Role: Constructed from 304-grade stainless steel, it safely channels surplus water to the drainage system when storage capacity is exceeded, preventing roof overload and maintaining system integrity.

Attenu8® Diffuser/Access

• Function: Provides access and inlet diffusion with silt trap.

• Role: Comprises a base, riser, and slotted/solid cover, all made from 304-grade stainless steel. It facilitates maintenance access to flow restrictors and outlets while diffusing incoming water and trapping sediment to maintain system efficiency.

Attenu8® Lite Attenuation Layer

• Function: Lightweight drainage layer for low-load applications.

• Role: A 55mm-thick polypropylene layer used instead of heavier cells in less demanding scenarios. It supports water attenuation in blue, green, or blue-green roofs, offering flexibility for varied structural requirements.