Roof Rainwater Runoff Calculator

This is especially important if you are installing a rain catchment system for use in irrigating your garden or lawn.

Roof rainwater runoff calculator.

Wondering how much rainwater you could collect off your roof. Contemporary houses often have flat roofs which shouldn. As your roof surface is the catchment area for harvesting rainwater it s important to know how large or small it is so you can calculate how much rainwater you can expect to harvest. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.

However flat roofs are not really flat. Take the dimensions of the footprint of your roof and convert them to inches. They would be more accurately called low slope roofs. However calctool s unit menus remove this issue doing all the unit conversion for you.

What is the standard pitch for a roof. Use this rainwater harvesting calculator to find the answer. In this example 600 x 240 x 1 144 000 cubic inches of water. Getting water off a flat roof sounds like a tricky scenario.

Calculate the total area of your roof. A simple rain catchment system can provide water for outdoor use resulting in. Box gutter with rain water head at end of box gutter. Rain barrels store and reuse rainwater helping to reduce the overtaxing of sewer systems and protect the quality of groundwater.

For a rectangular house this is simply done by multiplying the length by the width of the roof. Here you can easily find how much rainwater you can collect from you roof how much you need to remove from a courtyard or how much runoff you can expect from an area of land. Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments. When planning your home and landscaping drainage needs it is necessary to accurately calculate the amount of rain runoff from your roof.

How to calculate roof runoff. To calculate the runoff from any given rainfall. With the proper roof slope and drainage installation precipitation is not a problem for buildings with flat roofs. Before you know what size rain barrels or cisterns to install you will need to calculate the average amount of rain runoff from your roof.

Calculating your roof surface area building plans offer the easiest way to calculate your roof surface area after all the numbers should all be on there.