By Sam Wasson
Updated Nov 14, 2022
While vital for keeping water away from your foundation, gutters occasionally require special care and attention to keep them clean and functioning. If not properly maintained, gutters can become filled with debris, begin to clog, and even eventually start growing mold. This mold will grow along the undersides of your gutters, coating them with grime. If left unattended, you can wind up with mold-damaged eaves, weakened shingles, and mildew stains.
This article goes over how gutters get mildew and everything you need to know to eliminate it.
There are two major reasons why your gutters are molding, one, the gutters have not been properly maintained, and two, your gutters are older or installed incorrectly. If your gutters are not consistently cleaned, unclogged, and maintained, they’ll build up large amounts of plant and animal waste over time. While cleaning out your gutters can be an unpleasant chore, as a homeowner, you’ll want to take care of them to ensure they’re in tip-top shape.
For older gutters, mold can be a warning sign of structural damage or the need for repairs. As gutters age, the connections between gutter pieces will loosen and produce small gaps. These gaps will eventually collect plant matter and moisture, which will cause mold growth. Furthermore, the weight of older gutters will cause the screws or spikes attaching the hangers to the fascia to sag. This lilting will expose these holes and the wood behind the gutters to the elements. Now exposed and unprotected, this wood will begin to develop mold around the spike holes.
You should immediately remove mold from your gutters after thoroughly cleaning and de-clogging the rest of the gutter system. We recommend cleaning your gutters twice per year, once at the end of fall and again at the end of spring. Cleaning your gutter system and removing mold at these times has several benefits:
Gutter cleaning and DIY mold removal require the right tools. We’ll separate the tools into two groups, one for general gutter cleaning and the other for specifically removing mold.
To clean your gutters, you’ll, at minimum, need:
To safely remove mold from your gutters, you’ll need:
One final note on using the proper tools: some home improvement sites recommend using a pressure washer (or power washer) for gutter cleaning and mold removal. We don’t, as pressure washing or soft washing gutters can lead to damage, like weakened connectors. Using bleach, warm water, a scrub brush, and a sprayer is enough to get mildew off.
The first step in removing the mold from your gutters is ensuring the rest of your gutter system is free and clear of debris. Removing mold from all the nooks and crannies it can hide in will be impossible if your gutters are clogged with plant matter. If your gutters are already clean, feel free to skip ahead to the instructions.
To clean out your gutters, you’ll need to:
Now let’s look into how to clean mildew from your gutters.
Moldy gutters are not only unsightly, but they also pose a risk of structural problems. As the mold grows and festers, it will weaken the surrounding wood structures, leading to sagging, moisture damage, and even collapse. If you have gutter mold, we recommend thoroughly inspecting your gutter system after it’s cleaned. Look for unsecured connections, sagging gutter sections, and loose hangers. If you experience constant gutter mold problems, it might be a sign of more serious structural failings, and you should hire a professional to inspect your gutter and roof systems.
Other Gutters Resources