Gutter And Downspout Design Calculations

First we will find the maximum amount of rain that will be captured in gallons per minute.

Gutter and downspout design calculations.

The downspout size must suit the bottom width of the gutter. Design of roof drainage systems roof drainage the roof is one of the most essential parts of a building as it protects occupants contents and interior of the structure from the elements. Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation. Doubling the number of downspouts halves the required capacity for each.

I certify that the roof gutter and downspout type size gage roof gutter slope and mounting. 3 by 4 inches 1 200 square. 2 4 gutter and downspout sizing and location calculations both metric and english units. We will use the larger of the two or 310 sq ft for our first calculation.

2 by 3 inches 600 square feet. In section iv of the design guide is a sample design which includes design calculations and plan sketch. The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts. The following is a list of the minimum required design.

As with gutters a downspout s capacity must match or exceed the expected runoff. This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc. Once an architect has. Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts.

Size downspouts to fit the gutter. Remember to save this spreadsheet to your own computer. Featuring durable plastic construction this extension can be buried bent or connected to additional sections. Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.

15 m is a practical maximum gutter length to be served by a downspout. Please lower the maximum spacing between downspouts to see this effect. The gutter outlet capacity should suit the downspout capacity. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.

Use the chart below to figure out how many extra downspouts you need. The design of gutter and downspout assemblies is an area of building design which demands special attention. Section ii design data record on appropriate engineering paper. Downspout sizes must not exceed the bottom width of the gutter.

To limit the effects of thermal expansion in gutters 50 ft. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.