Upstream Change of Direction Solutions

Dam Buster Elbow (ELB), T Junction (TJN) and Corner Junction (CJN) devices are only designed for use at locations upstream of the point of discharge.  Available in various combinations, they are able to safely change the direction of water in a box gutter by ninety degrees. 

IMPORTANT: If you want to change direction at the point of discharge instead, please see our TSO, ESO, CSO and XSO range HERE.

The change of direction is achieved by Dam Buster's fully engineered and tested step down in the device. 

These amazing products provide huge flexibility in roof drainage design whereby box gutters can be directed easily and safely around corners and obstructions, or joined with each other, then routed to a more appropriate outlet point some distance away.   Nobody else has these solutions other than Dam Buster. 

Our devices require absolutely no pipe work and also have very minimal clearance - depending on the device the clearance is between 50mm minimum, and 70mm maximum.  This flexibility and easy of use in turn reduces installation and construction costs while providing incredible design freedom. 

Various versions are available, to suit box gutters between 200mm and 600mm wide, but as with all of our products, sizing ultimately depends on the flow rate being dealt with, and the corresponding flow rate at the end outlet.  

All three devices are available in a contracting version as standard.  This means they can be adjusted on site by the installing plumber without any extra tools to precisely suit any incoming box gutter width.  Fixed versions are also available (to special order). 

Product dimensions can be found HERE.

For even more information, please download our Product Technical Statement HERE and refer to the Product Data Sheets.

NB: Requirements vary from state to state but generally a Performance Solution is required for installation certification purposes of these Dam Buster devices; that document should be developed by a suitable expert such as a qualified hydraulic engineer, in accordance with the requirements of the National Construction Code. Documentation to assist the development of a Performance Solution - including Template Documents for all states and territories - can be sourced here at Technical Downloads

Please Contact Us for more information.

Elbow (ELB-xxx) (Left or Right)

Corner Junction (CJN)

Corner Junction (CJN-xxx)(L or R)

Tee Junction (TJN-xxx)


But How Does It Work?

The Dam Buster upstream change of direction devices are carefully engineered to work like a free flowing river and waterfall.  See the video on the left showing the Elbow at work. 

Analysis by Dam Buster’s hydraulics engineering expert, Adjunct Assoc. Professor Dr Robert Keller of Monash University Melbourne, along with extensive physical testing, has confirmed that the energy loss at the 90 degree bend in the Dam Buster device is less than the energy released by the engineered drop built into the device, and consequently backwatering cannot occur in the box gutter. 

The physical testing also confirmed there is significantly more freeboard in the critical locations within the devices than is required under the applicable standards, and finally, the additional energy released from the built in drop also enhances self-cleaning of the box gutter. 


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