Rainwater outlets are essential components of a building’s drainage system. Their primary purpose is to collect and discharge rainwater from roofs, balconies, and other horizontal surfaces, ensuring that water does not accumulate and cause damage to the structure or create safety hazards.

Overflow systems act as a backup drainage solution. If the primary roof outlet becomes blocked or overwhelmed, the overflow outlet allows excess water to escape, preventing ponding and potential flood damage to the building structure.

They are typically installed in the lowest points of a surface to allow gravity to direct water toward the outlet, from where it can be guided to downpipes or drainage systems.

• SPS and Metabronze Rainwater Outlet are designed to integrate with membranes and roofing systems to ensure watertight connections. Drains are compatible with EPDM, TPO, and Butynol membrane surfaces, as well as cement and asphalt toppings.
• SPS heavy-duty grates are engineered for vehicular crossing and are load tested to Class D of AS3996-2006.
• ‘SuperFlow’ rainwater drains, equipped with 150mm and 225mm outlets and larger grate dimensions — unique in New Zealand — provide exceptional water flow capacity. These drains are designed for areas prone to prolonged rainfall or flash flooding, ensuring reliable performance in challenging conditions.

Key Uses:

• Flat and Low-Slope Roofs: Designed to prevent water ponding on flat roofs by directing it into the drainage system.
• Terraces and Podium Decks: Collect rainwater to prevent infiltration into the building structure.
• Balconies and Walkways: Manage smaller volumes of runoff and prevent surface water buildup.
• Carpark Decks: Manage surface water efficiently in areas subjected to vehicular traffic and heavy load-bearing conditions.

• Structural Protection: Prevents water buildup that can cause leaks, mould, or structural weakening.
• Safety Enhancement: Reduces slip hazards from pooled water on walkways and decks.
• Aesthetic Preservation: Prevents unsightly water stains and damage on building exteriors.
• Supports Sustainable Drainage: Can be connected to rainwater harvesting systems or sustainable drainage systems.
• Prevents Roof Damage: Eliminates excessive load from standing water, which can deform or damage roofing systems.
• Compliance with Building Codes: Ensures buildings meet drainage regulations and best practices.
• Environmental Objectives: Metal components such as bronze, cast iron, and stainless steel are recyclable, supporting sustainability objectives and contributing to the long-term value of building assets.

Rainwater outlets are crucial in efficiently managing surface water and protecting buildings from water damage. Their design, material selection, and proper installation are essential for ensuring the long-term health of a structure’s roofing and drainage system. When chosen and maintained correctly, they provide a robust, low-maintenance, and sustainable solution to rainwater management.

Show more

SPS Rainwater Outlets are designed and manufactured to meet the requirements of the New Zealand Building Code (NZBC), specifically Clauses E1 (Surface Water) and E2 (External Moisture), along with their Acceptable Solutions E1/AS1 and E2/AS1.

NZBC Clause E1: Surface Water:

• Purpose: E1 requires buildings to manage surface water effectively, ensuring that rainwater is collected and disposed of so that it does not enter buildings or cause property damage.
• Compliance: SPS rainwater outlets are engineered to provide efficient drainage from roofs and other surfaces, minimising the risk of water ingress, blockages, or overflow. Their design and capacity align with the performance requirements of E1, ensuring surface water is safely directed away from the building envelope.
• Acceptable Solution (E1/AS1): By following the construction details and installation practices outlined in E1/AS1, SPS rainwater outlets are deemed to comply with the code. This includes correct sizing, placement, and integration with waterproofing systems to ensure reliable surface water disposal.

NZBC Clause E2: External Moisture:

• Purpose: E2 focuses on preventing external moisture from penetrating the building envelope, which could otherwise cause damage or health issues.
• Compliance: SPS rainwater outlets are compatible with modern waterproofing membranes (such as torch-on and TPO systems). Their robust construction, made from materials like stainless steel, cast iron, bronze, and aluminium, ensures long-term resistance to corrosion and moisture ingress.
• Acceptable Solution (E2/AS1): SPS outlets can be specified and installed under E2/AS1, which provides prescriptive methods for integrating drainage components with waterproofing systems at critical roof and deck junctions. This ensures that the outlets contribute to a continuous, watertight barrier as required by the code.

Additional Qualities Supporting Compliance:

• Watermark Certification: SPS rainwater outlets are Watermark Certified, confirming they meet relevant New Zealand and Australian standards for plumbing and drainage products.
• Independently Tested: Products are independently tested for performance, including water flow capacity and durability, supporting their suitability for code-compliant installations.
• Track Record: SPS products have a proven history of use in commercial and residential projects, demonstrating enduring performance and acceptance by building consent authorities.

Note: Compliance is contingent upon correct selection of the drain outlet size, the number of outlet drains provided for use, and the correct installation process.

Show more