Gutter And Downspout Design

For practical purposes the roof gutter depths and areas used are assumed to hold true for all available gutter of a given style top width and material even though differences do occur.

Gutter and downspout design.

The gutter outlet capacity should suit the downspout capacity. Maintenance durability and longevity are important factors to consider when designing gutters and downspouts. Make the gutter out of galvanized metal. The design of gutter and downspout assemblies is an area of building design which demands special attention.

Connect areas c and b with one gutter. Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts. The flows and capacities of the roof gutter and downspouts shown in this design guide are based on actual measurements taken from some of the materials available. The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts.

Offset of more than 10 ft 3 0 m can affect drainage capacity. The proper slope is 1 inch down for every 20 feet of gutter. Measure the distance between each downspout and draw a thick line through the exact middle point between them. The downspout size must suit the bottom width of the gutter.

Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. Use the chart below to figure out how many extra downspouts you need. In addition to gutter and downspout design the functionality and long term performance of your roof drainage system is critical. Featuring durable plastic construction this extension can be buried bent or connected to additional sections.

If not designed with sufficient capacity quality of materials and finish and correct installation the building structure is vulnerable to roof leaks structural degradation to both roof and wall structures foundation leaks and or decay and ground erosion. Then run two downspouts to the storage tank as shown on the house drawing. The following are detailed gutter design drawings based on the data that you entered above. Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.

3 by 4 inches 1 200 square feet. Connect areas d and a with one gutter. As with gutters a downspout s capacity must match or exceed the expected runoff. Please lower the maximum spacing between downspouts to see this effect.

2 by 3 inches 600 square feet. Wide or a 117 mm 4 1 2 semicircle. Leaking gutters and downspouts can cause serious damage to a building s interior as well as exterior and repairs can be expensive.