Patent attributes
A bi-functional roof drain includes a housing forming a drain manifold and a drain outlet to connect to a drainage system. A vent pipe penetrates the housing and extends through the manifold. The top of the vent pipe is positioned a distance above the housing, which may be variable. With this drain, a method of retrofitting a roof drainage system to provide water drainage and system venting is also presented. This method includes removing an existing uni-functional roof drain from a deck penetration through the roof, and installing a bi-functional roof drain in the same deck penetration. The drain outlet is connected to the drainage system and the vent pipe is connected to the system that requires venting. The height of a top opening of the vent pipe of the bi-functional roof drain may be adjustable in relation to a surface of the roof.
