What’s the Right Amount of Downspouts for Your Roof?

Roofs
Photo of a downspout connected to a roof gutter

    Get a Free Estimate

    Enter your information below, and we'll follow up to discuss your needs and goals so we can get you a no-hassle estimate!

    icon of a sun with a check markBy submitting this form, you authorize Divided Sky Roofing & Solar to text, call, and email you regarding your inquiry.

    Roof downspouts are an essential part of any roofing system. They channel rainwater runoff away from your home and help prevent water damage by directing it to suitable locations away from the house. The more downspouts you have, the better; they serve as a secondary drainage system that you can use in addition to gutters or other primary drainage systems.

    Measure Your Roof to Find Out How Many Downspouts You Need.

    The first step in installing downspouts is to get a handle on exactly how many you need. This can be estimated based on the size of your roof and where water is likely to collect. The roof on a two-story house will also likely need two downspouts on each side of the roof. Placing them on the sides furthest away from the house is a good idea to ensure that excess water travels as far away from the structure as before draining.

    Determine The Best Locations for Your Downspouts.

    Once you know how many downspouts you’ll need, it’s time to decide where they’ll go. The best locations for downspouts are the spots where water tends to collect. For example, if your covered porch collects water, placing a downspout right at the edge of the porch is a good idea. The same is true of low spots on the roof where water tends to accumulate. It is a good idea to place your downspouts in these locations to prevent water from gathering and potentially overflowing.

    Install 2″ Diameter Downspouts Along Most of The Roof.

    For most roofs, 2″ diameter downspouts are sufficient. They are typically long enough to reach the ground and still allow some room for runoff to travel away from the house. You will want to install 2″ downspouts in the long run along the entire roof. Because 2″ downspouts are suitable for most roofs and easy to install, it is a good idea to start with these along most of the roof.

    Add 3″ Diameter Downspouts Only in Special Circumstances.

    3″ diameter downspouts are longer and heavier than 2″ downspouts, which means they will be more effective at draining water from the roof. They are also easier to install, requiring fewer fittings and connectors. You will generally want to use 3″ downspouts in any area where the 2″ downspout will not be sufficient, such as when a 2″ downspout would interfere with an important roof feature like a skylight.

    Ensure All Your Downspouts are Connected to a Rainwater Pipe or Pit.

    All downspouts should connect to a rainwater pipe or pit, even if they are only 2″ in diameter. It is generally a good idea to use a rainwater pipe as the connection point simply because it is more convenient. One option is to connect your downspouts to a downspout pipe that runs along the edge of the house, just below the level of the gutters. You can connect the downspout pipe to the gutter with a T-joint. Another option is to connect your downspouts to a rainwater pipe that runs along the roof’s edge.

    Conclusion

    Downspouts are an essential part of any roofing system. They channel rainwater runoff away from your home and help prevent water damage by directing it to suitable locations away from the house. The more downspouts you have, the better, but remember to consider everything discussed above before you install new downspouts for your roof.

    Recommended for You