The Roof Drain Calculator below is based on the maximum amount of rainfall in inches per hour of the hypothetical worst storm in the past 100 years.

Calculators for designing eaves gutters, box gutters, downpipes, pipes and open channels etc to Australian Standards. How to Calculate Roof Areas · Page for Roof Gutter Design · Box Gutter, Side O'Flow

Gravity System Roof Drainage Calculator - SS 525: 2006. The following tools are programmed to facilitate the design of gravity roof drainage systems, ...

Alumasc Water Management Solutions leading Drainage Calculator allows Architects, Specifiers and Building Engineer's to design and quantify all their Rainwater ...

The tools guide the user step by step allowing fast and simple roof drainage design whilst ensuring full compliance with BS EN12056-3 rainwater drainage design ...

The calculations below are meant for drainage from flat roofs where water are expected to spread over the entire flat roof during rain. The flat roof must have ...

Standing water in your basement, driveway or yard? NDS quickly identifies drainage problems and selects the right solution to resolve issues at home.

Take the roof's total square footage and divide by the total square footage handled by one drain. The result is the number of drains needed. For example ...

Select the basic data required and then click the View button below. Rainfall Intensity Select Nearest Town.

The program will calculate the size and number of downpipes (downspouts, leaders) required, and the eaves gutter sizes for any roof.