What is a control flow drain? And, how do I select the right one for my blue roof application?
Control flow drains are designed to slow the rate of runoff from roofs during storm events. These drains typically have an insert with a weir that regulates the flow of water through the drain. They are available in a variety of heights. Generally, flat roofs have lower weir heights than sloped roofs. Some models have adjustable weirs which can be set for each drain / location, and some may utilize copper flanges to inhibit root growth. All control flow drain systems should be carefully designed by a licensed professional engineer. These manufacturers sell controlled flow drains: