Roof & Gutter Flow

Roof & Gutter Flow is a simple, practical tool for estimating roof drainage and gutter system capacity. Enter your roof dimensions, roof pitch, rainfall intensity, gutter size, slope, and downspout information to see how the system performs. Roof & Gutter Flow calculates estimated runoff and compares it with gutter and downspout capacity to help identify potential drainage limitations. Features include: • Roof runoff calculations based on roof dimensions and rainfall intensity • Gutter capacity calculations • Downspout capacity and loading estimates • Interactive downspout positioning • Visual roof and gutter drainage layout • Roof coverage and modeled gutter length • PASS/FAIL system capacity results • CAUTION notices for roof areas not served by the modeled gutter • Reference rainfall lookup by city and state • PDF report generation and sharing Roof & Gutter Flow is useful for homeowners, contractors, maintenance personnel, inspectors, and anyone who wants a quick way to evaluate a roof drainage layout. Results are estimates intended for reference and planning purposes. Local building codes, rainfall requirements, roof conditions, gutter installation, and other factors should be considered when designing or modifying an actual drainage system.