The Watts RD-400 is a large-area primary roof drain designed for commercial and industrial roof systems that require high-capacity drainage. Its epoxy-coated cast iron body provides long-term corrosion resistance, while the flashing clamp and integral gravel stop ensure a secure, watertight connection to the roof membrane. A large self-locking polyethylene dome helps prevent debris intrusion, and the drain is supplied with a standard no-hub outlet for straightforward installation.

Key Features

• Epoxy-coated cast iron body for durability and corrosion resistance

• Flashing clamp with integral gravel stop for secure membrane integration

• Large self-locking polyethylene dome for reliable debris protection

• Standard no-hub outlet for easy plumbing connection

• Suitable for large-area primary roof drainage applications