Gutter Drainage Work Estimate Needed
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
Gutter drainage work estimate needed. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Then use the chart below to see what size gutter you need. Installing 200 linear feet of gutters costs as little as 600 if you do the work yourself to as much as 2 500 3000 when hiring a contractor depending on the material you install. Working out gutter slope as a general rule gutter slope is set at 1 4 inch per 10 feet of guttering.
Using the table below will help calculate the volume of water to be stored. Cost to install gutters notes and general information. Work not mentioned on this page and or work using master craftsman premium materials and project supervision will result in higher costs. This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.
If a roof s various drainage areas call for different size gutters go for the biggest one k style. Multiplying by 15 minutes leaves you with the amount of gallons to be stored. The runoff for each zone was in gallons per minute. 5 inch 5 520 square feet.
For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e. Size downspouts to fit the gutter. 6 inch 7 960 square feet. To calculate the volume of water that needs to be stored multiply the amount of runoff from each drainage zone by 15.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.