The Watts RD-300-R is a medium-area overflow roof drain designed to provide secondary (emergency) drainage when primary roof drains are overwhelmed or blocked. Its epoxy-coated cast iron body offers long-term corrosion resistance, while the flashing clamp and integral gravel stop ensure a secure, watertight membrane connection. A raised external water dam sets the overflow height, and the self-locking polyethylene dome helps keep debris out. The unit is supplied with a standard no-hub outlet for straightforward installation.

Key Features

• Raised external water dam for controlled overflow drainage

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

• Flashing clamp with integral gravel stop for secure membrane attachment

• Self-locking polyethylene dome for debris protection

• Standard no-hub outlet for easy connection