Measure Rainfall On Roof

If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year.

Measure rainfall on roof.

The number of feet multiplied by 144 equals inches. Divide 100 by the number of downspouts in order to obtain the percentage of water collected from each downspout. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. In this example 600 x 240 x 1 144 000 cubic inches of water divide by 231 to get the number of gallons because 1 gallon 231 cubic inches.

Multiply the area of your roof by the amount of rainfall you wish to calculate for. Measure along the length of the house or building and along the width of the house or building in feet. To find how much rain you can collect in an average rain year multiply this number by the average inches of rain. Rainfall calculator english units how much water falls during a storm.

For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. Actually although we usually just say inches we really mean inches in the storm or inches in the last 24 hours or inches in some time period why does that matter. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

This capacity can be calculated using the following formula. Outside of the u s a degree angle is typically used. Use our metric system version. Rainwater collection calculation formulas and equations roof area ft 2 x precipitation amount in x 0 623 amount collected gallons.

Multiply the roof dimensions by the number of inches of rainfall. As you probably know rainfall amounts in the united states are typically measured in inches. Multiply the two figures together to obtain the square footage of your roof step 2 determine the percentage of water collected from each downspout p. It is the middle of july in georgia and both you and your tomatoes are wilting in your yard both looking to the sky and hoping for rain.

For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches. If you want to look at collecting from different areas of your roof you can always hit the clear area button to start over. Roughly speaking 1 millimetre of rain over 1 square metre of roof equals 1 litre of water. Count the number of downspouts coming from your roof.

Step 1 determine the footprint of your structure f in square feet.