How to Prevent Mold and Mildew on Your Stucco Exterior

Not many things beat the staying power of stucco. It’s durable, it’s energy-efficient, and it’s nice to look at! That doesn’t mean it’s perfect, though—really, nothing is perfect. Take its porous characteristics, for example. It makes your stucco exterior prone to mold and mildew, especially in humid or damp climates. These growths sure are ugly, but there’s more to it than that. They can actually cause the structure to weaken if left unchecked, meaning maintenance that could significantly lighten your pockets.

By understanding the causes of mold and mildew on exterior stucco, you can begin to take proactive steps, thus protecting your finish for years to come. Let’s take a look at what you can do for prevention and handling of mildew.

Understand Why Mold and Mildew Develop on Your Stucco Exterior

The porous nature of stucco is a blessing and a curse. It can breathe and maintain a (relatively) low weight, but moisture gets trapped easily. Mix this scenario with stucco’s ability to retain that moisture, and you’re looking at the perfect environment for mold and mildew to flourish. Be extra vigilant for such  signs if you’re in an area with high humidity, frequent rain, or even excessive shade. In addition, poor drainage or overhanging trees can make the problem worse by trapping moisture near the walls.

• Shaded Areas: Stucco in areas that don’t receive direct sunlight stay damp for longer periods of time.
• Clogged Gutters: Overflow from garden areas can cascade down the walls, basically creating an open invitation for mold to make itself comfortable.
• Standing Water: A landscape that’s graded towards the exterior stucco rather than away from it allows water to pool near the foundation, directly leading to mold issues.

When you understand these risks, you’ll be much more prepared to deal with them sooner rather than later. 

Regular Cleaning and Stucco Maintenance

One of the most effective things you can do to avoid unsightly exteriors and more costly stucco maintenance is simple, routine cleaning. It prevents mold and mildew from even taking root. How? The lack of visible issues doesn’t mean there’s nothing to clean. Dirt, pollen, and other organic material—food sources for mold—are constantly accumulating on the stucco surface. Removing this “food source” is akin to cleaning up food waste from a campsite to avoid a bear attack. 

To maintain that pristine exterior, take these steps:

1. Rinse off loose dirt with a hose or pressure washer on a low setting.
2. Apply a mild cleaning solution or specialized stucco cleaning solution.
3. Scrub gently using a soft bristle brush to avoid damaging the surface.
4. Thoroughly rinse the entire surface, as residue could attract additional dirt.

It’s advisable to clean these surfaces every six to 12  months to keep your stucco fresh and mold-free.

Improve Drainage and Ventilation

Moisture is the root cause of mold and mildew. That’s why it’s so important to maintain control of water flow around your structure. Here’s what you can do:

• Install a Proper Drainage System: Don’t skimp on your gutters and downspouts. Make sure you opt for quality materials and hire a trusted contractor to install them. They should direct water three to five  feet away from your structure’s foundation. Splash blocks and downspout extensions can’t hurt, either.
• Ensure Proper Grading: All of the ground surrounding your home should slope away from the structure. Otherwise, water can make itself right at home against your stucco. We all know what happens next.
• Enhance Ventilation: Are overgrown shrubs or trees blocking sunlight and airflow? Consider trimming them back so those dark areas can  get rid of their moisture more quickly.

Apply Protective Coatings to Your Exterior Stucco

Protective coatings can work wonders for your exterior stucco by seriously reducing its ability to absorb moisture. You can invest in a waterproof or mold-resistant sealant that will add longevity to the lifespan of your stucco. Just make sure you’re diligent when applying the sealant:

• Choose the Right Product: Breathable sealants designed specifically for stucco are ideal. The breathability allows any trapped moisture to find its way out.
• Follow Application Guidelines: Give your stucco a thorough cleaning before beginning to apply the sealant. For even coverage, we highly suggest using a roller or sprayer.
• Reapply as Needed: Typically, a good sealant will last three to five  years. That said, it’s still a good idea to inspect it more frequently than that, and reapply if you notice anything amiss.

In addition to preventing mold, these coatings  do a great job enhancing your finish’s resistance to cracking and damage from the weather.

Inspect Your Stucco Exterior for Damage Regularly

Even the smallest crack has the potential to cause big problems for your exterior stucco. Regular inspections could mean the difference between peace of mind and costly stucco maintenance. Take some time to give your investment a look and make sure it’s in good health—especially after any significant weather events. Be on the lookout for hairline cracks, bulging, or soft spots. If you do notice anything that raises the alarm, don’t drag your feet on getting repairs performed. More significant damage will require a professional, and we’re happy to help you put it all behind you! 

Landscaping Considerations

Your landscaping choices play a bigger role in the condition of your stucco than you may think. But take some time to consider how your plants and your house interact, and it all makes sense. Those shrubs you’ve planted have root systems that create a moisture rich environment. The flower bed you put all that work into now creates a grade towards your stucco exterior, inviting rainwater to have a puddle party right against your home’s foundation.

Here are a few things you can do to make sure your landscaping isn’t hurting your stucco:

• Maintain Distance: Plant shrubs, trees, and bushes at least three  feet away from stucco walls.
• Adjust Sprinklers: If you have a sprinkler system, make sure it isn’t spraying water directly onto your stucco walls. As an alternative, consider a drip irrigation system.
• Use Moisture-Absorbing Materials: Gravel and mulch do a great job of absorbing moisture that would otherwise sit and damage your foundation.

Conclusion

Are mold and mildew always a risk when maintaining a stucco exterior? Yes. Is it easy to keep both at bay with relatively minimal effort and money? Also yes. By understanding what causes mold growth and what you can do to counter it, you can preserve the beauty and integrity of your stucco. And for the times when you need a more professional touch, our team can lend a hand. Get in touch and get ready for great stucco service!