How To Clean Mold Off Your Gutters

Where you have water, you tend to have moisture problems like mold and mildew. So it’s no surprise that gutters are susceptible to a buildup of mold. Mold spreads fast and can quickly damage your gutters and roof, so you should eliminate it immediately. Here’s how to clean mold off your gutters. 

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Why Should You Clean Gutters?

rain gutters pressure cleaning
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Gutters do their job efficiently only if they are clean. Clogged gutters are ineffective, and in fact, they cause more harm than having no gutters. 

Here are some reasons to clean your gutters

  • Prevent water from damaging your home’s foundation. 
  • Prevent roof damage. 
  • Prevent interior damage. 
  • Prevent pest infestations and mold formation.
  • Prevent expensive gutter system repairs
  • Enhance curb appeal.

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Why Do Gutters Get Mold?

Debris impedes water movement in your gutters. The moisture from stagnant water, along with debris, make your gutters the perfect place for mold to thrive. Mold multiplies extremely fast and can spread across your gutters and roof in just a few months. If you spot mold, clean it off immediately. 

Here are some reasons why your gutters get mold. 

  • Improper maintenance causes leaves and other debris to clog your gutters, restricting water movement. 
  • Incorrect installation causes dirt and water to collect between small gaps, inviting mold.
  • Old gutters usually attract mold as the gutter fittings loosen over time and form small gaps. Debris and moisture will collect between these gaps, causing mold growth. 

Cleaning Mold Off Gutters

worker cleaning leaves from gutters
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Cleaning mold off your gutters is a DIY task. Though unpleasant, this chore isn’t as difficult as you’d imagine. 

Tools Needed

  • Strong ladder 
  • Protective gloves and eyewear
  • Long-handled scrub brush 
  • Gutter scoop 
  • Garden hose
  • Bleach
  • Extendable sprayer

Best Time for Cleaning

We recommend you clean your gutters at least twice a year, during late spring when plants drop their seeds, and late fall when all the leaves have fallen. You may have to clean them more often if you have pine trees that frequently shed needles.  

Spring and fall are usually the wettest seasons in the United States, and cleaning your gutters then can prevent mold from forming the rest of the year. 

Don’t forget to consider the climate when cleaning gutters. It’s not a good idea to tackle this job when it’s too hot as it can cause heatstroke. Also, if it’s too cold or windy, the chances of slipping and falling off the ladder are high. 

Safety Considerations

  • Make sure to check your ladder before climbing. Also, place it on a stable, flat surface. 
  • Place the ladder close to the gutters to clean them without stretching too much. Getting down and moving your ladder for better reach is better than losing balance by overreaching and falling. 
  • Wear grippy boots or shoes. Don’t wear flip-flops as they lose grip easily. 
  • Don’t clean your gutters on a rainy or windy day. 
  • Wear a long-sleeve shirt and long pants, and ensure they aren’t too loose. Also, don’t forget to wear protective gloves and eyewear. 

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Step-By-Step Instructions

Here are the steps to remove mold from your gutters. 

Step 1: Prepare the Bleach Mixture

Mix one part bleach with three parts warm water and pour it into the spray bottle. Besides removing mold, this solution can also remove oxidation and clean the siding. 

Bleach solution can harm your skin and eyes, so don’t forget to wear your protective gloves, goggles, and protective clothing. 

Step 2: Place Ladder

Place your ladder on a flat surface and rest it on the wall. If you have gutter guards, remove them first. 

As mentioned above, never reach too far to clean gutters, as it’s dangerous. If you can’t reach a part of your gutter, get down, move your ladder, and then climb back up and continue. 

Step 3: Clean Your Roof

Clean your roof with a pressure washer or leaf blower, or hire a professional roof cleaner, before you start rinsing your gutters. You don’t want all that debris from the roof to make its way into the gutter after you finish cleaning.

Step 4: Remove Debris From Gutters and Rinse  

Use a gutter scoop to remove debris from your gutters. We recommend you scoop the debris from one corner to the middle and repeat the same on another side to prevent leaves and other debris from clogging the downspouts. 

Once you remove the debris, rinse your gutters with a garden hose. We don’t recommend pressure washing the gutters because it can weaken the connectors. 

Step 5: Spray Bleach Solution on All Moldy or Mildewy Areas 

Use the extendable sprayer to apply the bleach solution on all moldy areas in your gutters. You can also apply it over grime and gutter stains. 

Don’t expect to get rid of mold on the first pass, as the bleach mixture kills and weakens mold before removing it. You may have to reapply, scrub and rinse the mixture (see steps below) two or three times, but the finished product will be worth the effort.

Note: It’s not a good idea to grow plants under your gutters as they are prone to overwatering. But if you have any, cover them with a frost cloth before spraying the bleach solution. You can get a frost cover from your local Home Depot or Amazon. 

Step 6: Wait and Then Scrub

Give the cleaning solution 10 to 15 minutes to start working before scrubbing. In the meantime, douse your scrub brush in the bleach solution.

After 15 minutes, ascend the ladder and gently scrub the gutters. Don’t apply too much force when cleaning, as it can break the gutter connections. 

Note: Whether you have steel, vinyl, copper, or aluminum gutters, warranties generally don’t cover damage from cleaning. 

Step 7: Spray Bleach Solution Again

When you spray bleach solution this time, most of the mold will come off. It will also kill the remaining mold, which you can remove with the final rinse.

Step 8: Final Rinse

Wait 10 to 15 minutes for your gutters to absorb the bleach solution. Once done, rinse your gutters for the last time. 


What’s the difference between mold and mildew?

Mold refers to all microscopic fungi species that grow in hyphae (multicellular filaments). Mildew is a specific type of mold, usually with flat growth habits.

Is it possible to prevent mold entirely?

No. Gutters stay damp most of the time, inviting mold growth. You can prevent mold from spreading too much by cleaning your gutters twice a year. Also, if you notice mold, remove it immediately. 

How often should I clean gutters?

It’s best to clean your gutters at least twice a year, during late spring and late fall. 

DIY or Hire a Pro

Mold multiplies rapidly and can destroy your gutters and roof, besides looking unsightly. If you notice mold growing in your gutters, don’t hesitate to remove it immediately with a cup of bleach solution. With proper gutter maintenance, you can prevent mold formation to a great extent. 

We understand gutter cleaning can be unpleasant. It’s a task that homeowners hate, but letting debris buildup can cause heavy damage to your home’s foundation. Get in touch with MyGutterGnome gutter pros if you need help with gutter cleaning. 

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Main Image Credit: Lex20 / Canva Pro / License

Abdul Wadood

Abdul Wadood understands that gutters aren't something to be compromised with. He informs homeowners about the importance of installing a gutter system and helps them maintain it in good shape. When free, you can find him exploring the world.