Converting this to gallons per minute per square foot gpm ft 2.
Roof area to gallons.
Highly porous concrete roofs may require more coating for proper coverage.
Total roof area also affects runoff.
The runoff for the grass portion of drainage zone a is.
0 35 x 1 5 x 900 96 23 4 91 gpm.
Rainwater collection calculator in gallons.
Using a 10 000 sq.
Notice that even though the grass area is nearly 2x that of the roof the roof runoff is nearly 2x that of the.
A roof of 1 200 square feet in size will collect more water than one that is 600 square feet.
To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above.
Rain barrel supplies list.
Gutters and a downspout.
1 inch of rainfall in an hour will cover 1 sq ft.
Roof area ft 2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember.
Rainwater can be collected from the roofs using the rain water harvesting method.
Take the dimensions of the footprint of your roof and convert them to inches.
The runoff q for the roof area in drainage zone a is.
Multiply across each row.
Either way you would like to know how much rain has fallen how many gallons have come down from the skies onto your roof yard block or town.
For all three products allow one gallon of roof coating for every 80 square feet of corrugated metal roof or 100 square feet of smooth metal roofing.
Pitch or steepness also is a factor.
The answer is about 623 gallons.
Required roof drainage flow rate in gallons per minute 0 0104 x rainfall rate x roof area where rainfall rate is expressed in inches per hour and roof area is given in square feet.
In the form below choose an area s and a rainfall amount to see how many gallons of water fell from the sky onto that area.
1 00 x 1 5 x 500 96 23 7 79 gallons per minute.
1 of rain on 1 000 sf roof will yield 623 gallons roof area m 2 x precipitation amount mm amount collected liters other water conservation calculators.
Or 0312 gallons per minute sq.
For example a 3 inch per hour rainfall will build up to a 3 inch depth on a flat roof in one hour at the rate of 1 87 gallons per hour sq.
So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.
To calculate the runoff from any given rainfall.
Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water.
The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area.
An inch of rain is not much but it if falls in half an hour it could flood a gutter.
To a depth of 1 in 1 hour.
The total rainfall and how rapidly it falls will affect the runoff from the roof.