Gutter Downspout – What Are They & Why They’re Vital For Your Home!

gutter downspout

The anatomy of your home’s rain gutter system is pretty straight forward. 

In fact, one of the most important exterior components of your home (gutters) is one of the simplest to truly understand!

On your home, you have:

  1. Your seamless gutters sections (custom fit for your home), 
  2. Screw-in hidden hangers/brackets (replace old gutter spike style)
  3. Inside and outside corners for gutters with 90-degree corners
  4. End caps for gutter sections
  5. Drop outlet to connect to a downspout
  6. And lastly, your gutter downspout which directs water to a splash block

The reason for sharing the anatomy of your home’s gutter system with you is recently the team at Gutter Gurus of Woodbridge visited a home in Northern Virginia where we saw this:

As you can see the screen mesh gutter guard (which we never recommend) was lodged at the entrance of the gutter downspout causing a blockage. 

This blockage of leaves and organic build-up was preventing the water from draining down the downspout, thus leading to many other possible gutter issues. All this to say – your gutter downspouts are very important. 

Understanding Gutter Downspouts 101

Your downspouts are ultimately where all the water during rains will end up! 

First, water hits your roof, travels down the roof slope, and collects in the gutters. Next, traveling down a slight downward slope to the downspout, water rushes to and through your gutter downspouts to be displaced away from the home. 

Typically, as a general rule of thumb, depending on the size of your gutters (4in, 5in or 6in) there should be a downspout per 20 feet of guttering. However, factors such as weather and the aforementioned gutter size can determine if more or fewer downspouts are needed. 

Most homes don’t have gutter sections longer than 40 feet, so a downspout on each end works perfectly. 

Downspouts come in the following sizes: 

  • 2×3 inch downspouts for 5-inch rain gutters
  • 3×4 inch downspouts for 6-inch rain gutters

Most downspouts are made of aluminum, and it’s best to always avoid vinyl downspouts! Typically most homes require 3×4 inch gutter downspouts, but that depends on the location and size of a home and the role of your downspouts…

Gutter Downspouts Job

Simply put, the job of your downspout is to displace all the water your home’s gutters collect and place the stormwater away from the foundation of your home in designated areas. 

One of the reasons we recommend 6-inch gutters to homeowners is because the 6-inch gutters require 3×4 inch downspouts, which are capable of handling more rainwater during heavy rains compared to their 2×3 inch counterparts. 

In fact, the law of physics (Bernoulli differential) and the raindrop outlet where the downspout connects is wider with 3×4 inch downspouts, resulting in a 300% increase of displacing water. 

The goal of your downspout is to move water away from your home as fast as possible, however, no matter the size of your downspouts, if you’re gutters aren’t maintained and cleaned – they won’t work if backed up! 

This is why it’s important to keep your gutter downspouts free and clear of debris (like the video from earlier), or you can see these problems below.

Possible Issues with Downspouts

When a gutter is unprotected, as in they don’t have a reputable gutter guard like Rain Drop, the gutter downspouts can become clogged. 

Sticks can enter downspouts clogging them and leading to damming, thus preventing water from entering the downspouts. Even dead birds and bird nests can clog downspouts (more common than you might think). 

Downspouts that are damaged from clogs or hit with branches/ice can also become disconnected from the gutter section. This is very evident, especially during rainstorms.

Gutter downspouts that are not working can lead to: 

  • Erosion 
  • Mosquitoes (where water builds up)
  • Exterior leaks
  • Unattractive curb appeal

Either way, if properly maintained and inspected annually, these issues commonly arise. In the event the gutters downspouts do have some issues, there are always simple solutions. 

gutter downspout issues

Gutter Downspout Solutions

The quickest fix sometimes consists of simply grabbing a ladder and checking out your gutters and downspouts. 

If a gutter downspout is clogged, unclogging it, as in the video from earlier shows, allows water to quickly drain down the downspout as prescribed. That being said, this also means you should also clean gutters regularly. 

Cleaning gutters isn’t too challenging, however unclogging a clogged downspout isn’t always a simple process. Best case – a downspout is covered at the top and simply needs cleaning. Worse case, the downspout becomes disconnected or needs to be replaced. 

How to Measure Your Downspouts

A question we are sometimes asked is how to measure gutter downspouts, especially when using the Gutter Guru calculator. The process isn’t too hard, simply do the following:

  1. Count the number of bends (elbows) in your downspouts (like the photo shows below)
  2. Equate each bend to 1’ of aluminum downspout
  3. In between the elbows is typically 1-3’
  4. Then measure each the rest of the downspout either with a tape measure extending it up to your home -OR-
  5. Equate each floor as 8-10 feet of guttering downspout
gutter downspouts

For example, if this was a two-floor home, this downspout would be approximately 24’ in length. Downspouts and guttering can be inputted into a gutter calculator like this to get an instant gutter price: 

Final Word:

Now that you know way more about gutter downspouts then you would ever want to, here is to making sure your home’s gutter system is forever efficient and working!

When you have a question about gutters you know where to go! Be sure to get an instant custom gutter quote if you’re in the market using our gutter calculator!

Until next time, 


Gutter Gurus of Woodbridge, Va proudly serves the Northern Virginia region for all gutter services including gutter installation, gutter guards and gutter repair.