4 Ways To Know Your Downspout Is Clogged

Clogged Downspout Lg

We all hate cleaning gutters. Unfortunately, when gutters are not cleaned, downspouts can become congested and obstruct storm water flow. A clogged downspout is not only a hazard in your home but also a source of potential damage. It can cause flooding in the basement and destroy the foundation of your house.

Here are four ways to know your downspout clogs:

  1. water pooling at the downspout connection.
  2. water damage to the fascia boards or leaking in the basement.
  3. the gutters have standing water and frequently overflow when raining.
  4. there will be little to no flow out of the end where the downspout empties into the sidewalk, street, or driveway.

In this post, you will find out how to tell when your downspout is clogged. Also, I will explain how to clear it when this happens.

Here are the four telltale signs of a clogged downspout:

1. Water Pool At The Downspout Connection

For many homeowners, the lower end of a downspout connects to an underground French drain. The French drain is the pipe that leads water from the downspout away from the house to pour elsewhere.

However, if the downspout is clogged, the water flow into the french drain slows down, causing pooling around the connection.

The clog prevents the seamless flow of water from one pipe into another. As a result, the water accumulates at the connection and leaks out onto the ground around the downspout. 

When the clog is starting to build up, you may not see a lot of water pooling at the bottom of the downspout. But, you will notice a water stain (especially on the concrete near the downspout), and the area doesn’t dry up even when it is sunny.

2. An Overflowing Gutter

An overflowing gutter has water pouring over the edges. The overflow of the water causes some soil erosion right underneath the gutter.

In some cases, the water flowing out of the gutter causes the paint to peel. You may also notice that this section of the house is always moist.

This sign is the most obvious as the water overflow is quite extreme. The water has no place to go, so it pours over the edge in large quantities, especially if it has rained.

3. Leakage Inside The House

The basement and crawl spaces bear the brunt of water damage when your downspout is not functioning optimally. 

At first, water seeps into the basement walls. However, if the downspout is left unattended, the water begins to pool onto the basement floor. This water quickly damages the floor. 

You may also notice water pooling around the foundation of your home. This water impacts the structural soundness of the house.

4. No Flow Out Of The Exit Drain

When water flows through the downspout, it should drain out on the exit side. But if the water doesn’t drain out on the exit end, it means there is a partial or complete clog.

Here is a simple experiment to see if the downspout works:

Pour water down the downspout and wait for the water to flow out on the opposite end. If it trickles or the flow is slow, your downspout is clogged.

How To Clear A Clogged Downspout

Before you begin to clear a clogged downspout, remember the following:

  • You may have to climb up the roof. Ensure that you have safety gear, including the right shoes, mask, and gloves. 
  • You are likely to need help from someone else.
  • The weather needs to be favorable. It may not be a good idea to do this in the dead of winter.
  • Clean the downspout from the ladder, not from the roof.

1. Start With The Gutters

Clean out the gutters. To effectively unclog a downspout, you need to remove any leaves and debris from the gutter. That will enable you to have better access to the top opening of the downspout.

Climb a ladder and sweep off the leaves in the gutter. Any gunk can be scraped using a gutter scoop like the Gutter Getter 00101 Cleaning Scoop. Alternatively, buy the small plastic sandbox shovels for kids.

After removing the gunk, hose down the gutter and wash away any remaining debris and dirt. Now you are ready to tackle the downspout.

2. Begin At The Bottom

Start by clearing the bottom end of the downspout. That will mean you have to remove the extension at the base of the downspout. You do this by loosening and removing the connecting adaptor.

But this removal applies if you have a downspout that connects to a French drain. 

If your downspout doesn’t connect to underground drain pipes, the above step is not necessary. 

Wearing your gloves, reach into the downspout from the exposed end and trowel the offending material, including leaves, twigs, and other debris out. 

Some of the debris may not be easy to rake out. Use your water hose to loosen it before scraping it out.

3. Pour Water From The Top

Climb the ladder again and hose down the downspout from the top opening of the downspout. As the water flows down, it cleans and washes any remaining debris out of the downspout.

Remember, this is a two-person job. So have your partner watch the lower end of the downspout to see if water will flow out carrying leaves and other debris. If this happens, you have successfully unclogged the downspout.

However, if no water flows out, you still have a clog that you must clear. 

Now, you have to go the extra mile. What does that entail? Here we go!

  • Tap the sides of the downspout to figure out exactly where the stubborn clog sits. That requires you to go up and down the ladder, gently tapping on the pipe and listening closely for hollowness. The area that doesn’t sound hollow is where the clog is located.
  • Use a handheld auger like this DrainX Drain Auger Pro to loosen the clog from the bottom and the top. Alternatively, you can use a power tool like a leaf blower or power washer from the top opening to force the clog out through the bottom opening. They can help to dislodge the clog.
  • If you can’t locate the clog on your own, it is time to call in the professionals.

Can Clogged Gutters Cause Damage

Clogged gutters can cause the following damages:

  1. Rot The Fascia

The damp conditions that arise due to clogged gutters promote rot in sections of the roof like the fascia. 

  1. Damage To The Ceiling And Walls

When the fascia board is compromised, water from the gutter will leak into the house, damaging the ceiling, walls, and windows.

Any section of the house that features woodwork becomes vulnerable to rot, mold and bacteria.

  1. Insect Infestation

Insects like mosquitoes love stagnant water. Clogged gutters hold pools of water that attract mosquitoes. 

Also, the leaves and gunk attract bees and wasps looking for a place to build nests and breed. 

Should You Ignore A Clogged Downspout?

Clogged downspouts and gutters are silent and nefarious. You may not know the extent until signs of damage become visible. It’s a good idea to be proactive and clean your gutters once a year in the Fall. Considering gutter guards is also a helpful way to keep debris out of your gutters and downspouts.


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.