How Many Downspouts Do You Need?

Oh no, the gutters are leaking again! This always happens when the rainy season starts, huh?

You went out of your way to clean the gutters, but it’s still not draining properly. You look up at your gutters and everything looks fine… except there is one pesky section that’s overflowing.

It seems to be missing a downspout, right? Well… maybe. Here is the general rule of thumb for downspout spacing:

Professionals recommend placing a new downspout for every 25 to 35 feet of gutter, with a maximum length between downspouts being at 40 feet. Other factors such as a steep roof incline or heavy rainfall may require extra downspouts to allow for better water flow.

Keep mind, there may be other issues why your gutters aren’t working properly, but we’ll get into that soon.

Do you Need to Add Another Downspout to your Gutters?

Downspout Placement Rule: Gutter downspouts should be placed 25-35 linear feet apart, with a maximum distance of 40 feet.

To determine if you need to add another downspout to your gutter system, take a measuring tape outside and figure out the length between each gutter.

If your downspouts are further than 40 feet apart, it’s a good idea to add another downspout to promote proper water flow and to keep your current gutters from overflowing during heavy rainfall.

Here are a few tips when choosing to install a new downspout:

  1. Direct water away from your home: The downspouts need to direct the water away from your house, especially the foundation. So make sure the new downspout is pointing away from the house. Keep in mind, a cracked foundation is an expensive fix, so any prevention now can pay off big time in the future.
  2. Downspout sizing needs to match the gutters: You want to make sure both the gutters and downspouts have the same diameter so there is a proper seal. With mismatched gutter and downspout sizes, water will leak from the downspout and hit your siding/foundation (which nobody wants). We’ll go into this with more detail soon.
  3. Consider a Unique Downspout: Believe it or not, downspouts come in a variety of different options. You can put your downspout underground so the water flow doesn’t mess with your landscaping. You can install an adjustable downspout that can be moved up and down. You can add extra length to your downspout to avoid landscaping as well.
  4. Small sections may need a downspout: If you have a small section of gutter that’s not connected with the main gutter system due to your unique home/roof shape, you may need an additional downspout. It may feel silly installing a downspout for 5-10 feet of gutter, but it’s better than it overflowing during rainy season, right?

Gutter Downspout Sizing Guide

So you’re thinking about installing a new downspout (or maybe you just want to learn more about gutters),let’s figure out what downspout size you’ll need for your specific gutters and home.

Gutter TypeGutter SizeDownspout Size
K-Style5 inches2 inch x 3 inch
K-Style6 inches3 inch x 4 inch
K-Style6+ inchesCustom sizing
Half-Round5/6 inches3/4/5 inches*
*Downspout sizing with half-round gutters depends on total gutter drainage capacity. Keep in mind, half-round gutters do not have as high of water capacity as K-style gutters.

K-Style Gutters

Chances are your home has K-style gutters or “ogee” gutters.

K-style gutters have that name due to the shape of the profile somewhat resembling the shape of a K. They are considered the gold standard for water drainage as they can hold more water than other styles. For 5 inch K-style gutters, you’ll need a 2×3 inch downspout. For 6 inch K-style gutters, you’ll need a 3×4 inch downspout.

If you have even larger gutters than 6 inches, you’ll need a custom downspout size to support that amount of water flow.

Half-Round Gutters

Half-round gutters are less common, but homeowners like them due to the visual appeal. They are, well, half-round shaped or a semi-circle. This style of gutter does not drain quite as much as K-style, so the downspout sizing will depend a lot more on your specific situation and there is no cookie-cutter sizing guide.

In this situation, it’s best to talk to a professional in your area to get the ideal downspout sizing.

How to Install Downspouts that Aren’t Ugly

gutter downspout on back of house

It’s a common complaint that downspouts are ugly and that they mess with your the look of your homes landscaping.

Well, it doesn’t have to be that way.

Your downspouts can be painted to match your home’s siding if you want to hide them as much as possible. You can also position your landscaping such as bushes and flowers around the sides of the downspouts to cover as much of them as possible.

Note: Just don’t put your plants right in front of the downspout or they’ll get washed away when it rains.

Or you can go the opposite direction and paint your downspouts so they stand out. Instead of blending in with the house, now they are an extra pop of color. In this case, homeowners will paint the downspouts to match the trim to really make the home come together nicely. The gutters/downspouts will look more like crown molding instead of just gutters.

When the gutters, downspouts, and trim all match, there is something very satisfying about that look.

How Far Away Should the Downspouts Stick Out for your House?

Your downspouts can stick out as far as you want from the house. In fact, there is a lot of ways to do this. The general rule of thumb is to stick the downspouts further out if you have landscaping in the area, otherwise a typical downspout and concrete splash plate will do the trick.

Here are the different types of downspouts:

  1. Normal downspout: A normal downspout that directs water away from the home.
  2. Extended downspout: A downspout with an extra extension to avoid pushing water into landscaping.
  3. Underground downspout: The downspout is installed underground so the water can flow away from the home without an extra long downspout above-ground.
  4. Flip-up downspout: An extended downspout that can be flipped up or down depending on if it’s raining or not. (Just don’t forget to flip it down when it rains).
  5. Flexible downspout: This downspout extension can be bent to flow water around a corner or be connected with a different section.
  6. Roll-out downspout: This downspout will extended when enough water has built up in the system and roll back up automatically with the rain stops.

How Long Can a Gutter be with One Downspout?

At maximum, a single gutter should no longer than 40 feet with a single downspout. However, the ideal gutter length with a single downspout is 25-35 feet.

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