Mold-Resistant Shutters for Australia’s Humid Climates

The high humidity, coastal moisture and frequent rainfall across many regions in Australia can lead to prolific mildew and mold growth on improperly protected exterior shutters. However, certain material choices, design features, and maintenance steps can dramatically slow fungal growth even in persistently damp conditions.

This comprehensive guide covers the causes of shutter mildew, characteristics to look for when selecting mold-resistant shutters, prudent installation and care practices, and when shutter replacement may be warranted due to advanced mold damage. Follow the recommendations below to ensure your shutters maintain their clean appeal despite Australia’s challenging humid climates.

How Outdoor Conditions Cause Shutter Mildew

Several prevalent conditions promote fungal growth on exterior shutters across Australia’s coastal and tropical environments:

• Moisture – Frequent rainfall, high relative humidity, and ocean mist provide the continuous dampness mold and mildew thrive on. Interior humidity also causes condensation issues.
• Heat – Australia’s warm temperatures accelerate chemical processes and evaporation that increase mold risks. Heat also degrades protective coatings faster.
• Poor Sunlight Exposure – Shady, overcast conditions prevent periodic surface drying that reduces risks.
• Limited Ventilation – Still air pockets behind shutters prevent circulation drying. Hollow profiles and gaps thus help.
• Organic Dust – Airborne dirt, pollen and pollutants provide nutrients mold feeds on when they accumulate.

Managing these environmental factors is key to minimizing shutter mildew issues in prone regions. Both material selection and maintenance practices play pivotal roles.

Mold-Resistant Shutter Materials Selection

Choosing materials with inherent antifungal properties avoids growth issues:

PVC Shutters

• Polyvinyl chloride’s toxicity to mold prevents surface growth even in damp conditions.
• Hollow profile designs improve airflow to evaporate moisture faster.
• Lacks organic content mold needs for nutrients.
• Pigments with UV inhibitors added reduce material degradation from sunlight.
• Smooth surfaces resist grime accumulation. Easily cleaned with diluted bleach.

Aluminum Shutters

• Metal itself is inorganic stopping mold from utilizing it as a food source.
• Conducive heat transfer discourages surface condensation.
• Powdercoat paint system prevents unchecked moisture absorption into raw metal.
• Color coatings limit heat and UV degradation of surface finishes.

Teak Shutters

• Dense grain and natural oils dramatically slow water penetration—the requirement for fungal growth.
• Properly finished, teak’s hardness deters mildew over wood with softer pores.
• Saturated fats and organic acids in teak’s oils are natural fungicides.

Thermally Modified Woods

• Heating wood specially reduces surface starches and sugars mold feeds on.
• Maintains stability and hardness superior to unmodified woods.
• Improved water resistance over other natural woods except cedar and teak.

Select materials with inherent biological, moisture and UV resistance. Never install untreated raw wood in humid climates.

Mold-Preventing Shutter Design Features

Material selection alone is not enough— prudent design adds multilayered defense:

• Hidden rain gutters channel water away rather than allowing wet wood-to-wood contact.
• Weep holes at joints drain condensation buildup.
• Wide louvers and hollow behinds promote ventilation drying.
• Dark colored powdercoat finishes absorb sunlight heat to evaporate moisture before it accumulates.
• Applied biocidal coatings prevent spore adhesion and terminate mold growth.
• Copper hardware inhibitions discourage growth at contact points and seams.
• Removable slat designs allow easy cleaning behind shutters.
• Marine-grade waterproof sealing prevents unchecked moisture access.
• sacrificial trim pieces are replaceable if accumulation occurs.

Multifactorial approaches provide the strongest protection from persistent humidity and dampness. Never rely on just one method alone.

Professional Mold-Resistant Shutter Installation

Proper installation using proven techniques sustains mold resistance:

• Allow prescribed ventilation and drainage gaps behind shutters during mounting. Never tightly seal edges airtight.
• Apply recommended waterproofing sealants generously within joints using complete continuous beads without voids.
• Check for weep holes alignment along bottom shutter rails or hidden gutters to drain freely outward.
• Use non-toxic exterior rated caulks without food sources mold can utilize. Avoid pure latex.
• Prime and paint any exposed unfinished surfaces prone to moisture wicking for completion.
• Consider supplemental contact fungicides along hidden surfaces for high risk regions.
• Check for plumb/level fit alignment to encourage proper moisture runoff.

Expert installation creates a holistic system uniting material attributes and design factors against moisture risks. Never cut corners.

Preventative Shutter Maintenance Deters Mold

Consistent maintenance preserves your shutter’s mold resistance:

• Hand wash shutters to prevent dirt buildup mold feeds on. Use detergent and water or diluted bleach solution on PVC.
• Apply commercial mildew inhibitor coating like Wet & Forget annually to exposed shutter surfaces.
• Reapply exterior primer and paint every 2-4 years or when visible glossiness declines.
• Use UV and water-resistant lubricants on hardware to prevent binding from corrosion.
• Inspect sealants and gaskets every 2-3 years replacing any with advanced cracking or shrinkage.
• Check for condensation or grime buildup around joints, louver overlaps and hidden surfaces.

Diligent care is far easier than dealing with advances mold damage after the fact. Don’t allow small issues to proliferate.

When to Consider Mold-Resistant Shutter Replacement

If long-term outdoor mold damage becomes too severe, total shutter replacement may become the most effective permanent option:

• Pervasive surface staining where bleaching and cleaning is no longer effective.
• Visible mildew or algae continuing to rapidly return after repeated elimination attempts.
• Swelling wood and peeling paint indicating moisture and spores behind finishes.
• Weeping water through joints or hardware openings carrying mold internally beyond surfaces.
• Missing or damaged flashings, seals, and water management features allowing unchecked moisture.
• Prior inferior quality installations using substandard organic materials.
• New updated local building mold prevention codes make upgrades necessary.
• Restoration costs approaching 60-70% of new shutter replacement cost.

If deterioration remains superficial, professional restoration may be an acceptable interim solution before eventual replacement is needed.

Consult the Shutter Mildew Experts

This guide provides a broad overview of best practices for combating mold and mildew growth on shutters in Australia’s persistently damp climates. But each home presents unique risks. We offer custom solutions tailored to your specific conditions, architecture and shutter needs after onsite evaluation. Our experts stay current on the latest materials and technologies proven to withstand Australia’s challenging environment. Contact us today to discuss options for keeping shutters fungus-free for decades to come.