How To Tell How Many Downspouts Your Roof Needs

Downspouts are an essential part of your home’s gutter system. They exist to carry water down from your horizontal gutters to the ground. Downspouts should direct the water away from your home’s foundation. In doing so, they help protect your roof, landscape, siding, and foundation from water damage over time. So, how many downspouts does your home need, and how can you take better care of those downspouts? Keep reading to learn the basics.

Downspout Placement

The rule of thumb often used in the roofing industry is that you should have a downspout approximately every 25 – 40 feet along your roof’s edge. It’s best to err on the lower side of this range when possible. If your roof design allows for gutters every 25-35 feet, this is best. However, placing them up to every 40 feet apart is adequate when this is your only option.

Each downspout can only handle so much water. It is essential to have enough downspouts in your gutter system. Without enough downspouts, the water will not drain from your horizontal gutters quickly enough. It will have nowhere else to go but over the edge of the gutters. As it pours over the edge, it can cause damage to landscaping, your foundation, and your roof.

Overflowing Downspouts

Do you sometimes see water pouring over the edge of your gutters where they meet the downspouts? This could be because you don’t have enough downspouts, and the rain is coming down faster than your downspouts can drain. But it’s more likely that your downspouts are blocked.

Downspouts can become blocked with leaves and other debris. This usually happens if your gutters have been filled with debris for a while. Eventually, enough of that debris rinses down into the downspouts, and they also become blocked. They may let a slow trickle of water, but they can’t drain fast enough to keep up with the rainfall.

Damage Caused by Overflowing Downspouts

Overflowing, blocked downspouts are not a problem to ignore. This issue can lead to several types of structural damage if allowed to persist.

  • Roof Damage. When your downspouts are blocked, water will back up onto the roof. Constant exposure to water can cause the shingles along the edge of the roof to lift. This puts you at risk for roof leaks and the need for premature roof repairs.
  • Siding Damage. When water flows over the gutter edges instead of down the downspouts, it often flows down the siding. This water is not clean. The debris it carries can cause streaks and stains on your siding. Plus, the constant exposure to moisture can cause the siding to grow algae or mold. 
  • Landscape Damage. Your gutters are 12 or more feet off the ground. So, any water flowing out of them will be traveling pretty quickly by the time it reaches the ground. This pounding water can create holes and divots in your garden beds. If it tumbles directly onto plants, it often kills them.
  • Foundation Damage. After the water falls from the gutters and lands in your garden beds, it saturates the soil near your home’s foundation. Over time, this over-exposure to moisture can lead to cracks in the foundation. Or, if your foundation is already cracked, you may end up with water in your basement. Wet basements come with their own share of issues, from mold to insect infestations.

Cleaning Your Downspouts

To prevent the damage discussed above, you must keep your downspouts clean. Start by keeping your gutters clean. Climb up on a ladder, scoop out the debris, and then rinse your gutters twice a year. There will be far less debris to flush into your downspouts and clog them.

If your downspouts are already blocked or are developing a blockage, you need to have them cleaned. If you’re confident on a ladder and have basic DIY skills, you can tackle this project yourself. Follow these steps:

  1. Stuff a towel or cloth into the top of the downspout.
  2. Feed a garden hose up the downspout, and turn on the water. This often flushes the debris out of the downspout.
  3. If there is still a blockage, remove the hose and towel, and feed a handheld auger down into the spout. Twist as you go to loosen the debris.
  4. Pull the auger out, and rinse the downspout with water.

If you have trouble cleaning your downspouts, hire a professional. Companies that clean gutters can usually clean your downspouts and gutters at the same time. 

If your downspouts are still overflowing after being cleaned, you may need additional downspouts added to your roof. Contact Bill West Roofing in Lee’s Summit, MO, for an estimate. We offer seamless gutter installation and repair, and we’ll make sure your home is protected.

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