The Flat Roof Drain (Zurn 100C) is engineered for commercial and industrial roofing applications where efficient stormwater management is essential. Its dual-outlet design provides enhanced flow capacity and system redundancy, making it ideal for buildings exposed to heavy rainfall. In this blog, we’ll break down the Flat Roof Drain’s features, installation considerations, and highlight a case study that demonstrates its proven reliability.

Flat Roof Drain – Installation Schematic

What Is a Flat Roof Drain?

A flat roof drain is designed to remove water efficiently from low-slope or level roofing systems. The Zurn 100C Flat Roof Drain uses a dual-outlet setup, allowing water to discharge through two separate paths. This increases overall hydraulic capacity and provides backup protection if one outlet becomes blocked, ensuring reliable roof drainage in demanding conditions.

Key Features & Benefits

• Dual-Outlet Design: Provides added capacity and redundancy for high-performance drainage.
• Heavy-Duty Construction: Built from durable materials designed to withstand long-term exposure and harsh weather.
• Dome or Strainer Options: Prevents debris from entering the system while maintaining flow efficiency.
• Flexible Integration: Multiple outlet sizes and connection types available for versatile installation.
• Reliable Safety: Reduces risk of ponding water and overflow during severe storms.

Zurn Brand Reliability

Applications & Use Cases

• Commercial flat roofs exposed to heavy rainfall
• Industrial facilities with large roof areas requiring efficient drainage
• Institutional buildings (schools, hospitals, labs) with critical overflow protection needs
• Retrofit projects upgrading older single-outlet roof drains
• Designs needing balanced flow distribution across piping systems

Installation Tips & Best Practices

To maximize performance, follow these best practices when installing a flat roof drain:

• Locate the drain at the lowest section of the roof for natural water collection.
• Select proper outlet sizes to balance both discharge paths.
• Install dome or strainer covers to reduce clogging from debris.
• Seal the flashing clamp or membrane carefully to maintain waterproofing.
• Test under high-flow conditions to confirm both outlets work as intended.

Flat Roof Drain – Technical Schematic

Case Study: Multi-Tenant Office Complex

Challenge: A large office complex faced frequent drainage issues during heavy storms. Single-outlet drains were prone to blockages, creating overflow risks and potential water damage.

Solution: The facility upgraded to Zurn Flat Roof Drains. Each drain used dual-outlet discharge, increasing system redundancy and flow capacity.

Outcome: Over two storm seasons, the building experienced no overflow events. Even when one outlet required service, the second outlet maintained reliable drainage, reducing maintenance costs and downtime.

Conclusion

The Flat Roof Drain (Zurn 100C) is an effective solution for modern flat roof systems. Its dual-outlet design, strong construction, and adaptability make it well-suited for commercial, industrial, and institutional projects. With proper installation and maintenance, it provides long-term protection against roof ponding and overflow.