Roof Rainwater Runoff Calculator

Contemporary houses often have flat roofs which shouldn.

Roof rainwater runoff calculator.

How to calculate roof runoff. Wondering how much rainwater you could collect off your roof. They would be more accurately called low slope roofs. This is especially important if you are installing a rain catchment system for use in irrigating your garden or lawn.

When planning your home and landscaping drainage needs it is necessary to accurately calculate the amount of rain runoff from your roof. Getting water off a flat roof sounds like a tricky scenario. Take the dimensions of the footprint of your roof and convert them to inches. 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.

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. Box gutter with rain water head at end of box gutter. For a rectangular house this is simply done by multiplying the length by the width of the roof. 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.

However calctool s unit menus remove this issue doing all the unit conversion for you. Use this rainwater harvesting calculator to find the answer. To calculate the runoff from any given rainfall. 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.

With the proper roof slope and drainage installation precipitation is not a problem for buildings with flat roofs. Rain barrels store and reuse rainwater helping to reduce the overtaxing of sewer systems and protect the quality of groundwater. A simple rain catchment system can provide water for outdoor use resulting in. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.

Calculate the total area of your roof. 512 490 0932 501 w powell ln 206 austin tx 78753 harvesting rain conserving water and managing stormwater in texas since 2004. In this example 600 x 240 x 1 144 000 cubic inches of water. However flat roofs are not really flat.

Although this calculation is simple in principle the units can make it a headache.