Cumaru Decking: Plan Maintenance Before Choosing a Material

Understanding Cumaru's Natural Characteristics

Cumaru is a tropical hardwood known for its strength, hardness, and natural resistance to insects, rot, and fungi. This robust nature means Cumaru decking is built to withstand demanding conditions. It also carries a Class A fire resistance rating.

When first installed, Cumaru typically exhibits a range of reddish-brown hues. Over time, if left untreated and exposed to the elements, it will naturally weather to a soft, silver-gray patina. The choice to maintain the original color or allow it to silver is a primary decision that shapes your maintenance plan.

Option 1: Embracing the Silver Patina

If you prefer a low-maintenance approach and appreciate the weathered aesthetic, allowing your Cumaru deck to silver naturally is a viable option. This choice significantly reduces the frequency of intensive maintenance tasks.

The primary maintenance for a silvered Cumaru deck involves routine cleaning to remove dirt, debris, and mildew. A simple sweep with a broom, followed by washing with water and a mild detergent, is typically sufficient. Occasional pressure washing on a low setting can help restore its appearance if surface grime accumulates, but care must be taken to avoid damaging the wood fibers. This approach avoids the need for regular oiling or sealing, saving time and material costs over the years.

Option 2: Maintaining the Original Color

To preserve the rich, reddish-brown tones of new Cumaru decking, regular application of a suitable oil-based finish is necessary. This approach requires a more consistent maintenance schedule but rewards you with a deck that retains its initial vibrant appearance.

The frequency of reapplication depends on several factors, including sun exposure, foot traffic, and local climate. Decks in full sun or with heavy use may require oiling annually, while shaded decks might need it every 18-24 months. Before reapplying oil, the deck should be thoroughly cleaned to remove any surface dirt, mildew, or old finish. This often involves a specialized deck cleaner designed for hardwoods, followed by a rinse and complete drying.

Essential Cleaning Practices for All Cumaru Decks

Regardless of whether you choose to let your Cumaru deck silver or maintain its color, regular cleaning is fundamental. Debris such as leaves, dirt, and pollen can accumulate on the surface, trapping moisture and potentially leading to mildew growth. Sweeping or blowing off your deck weekly or bi-weekly, especially after strong winds or rain, is a good habit.

For a deeper clean, a soft-bristle brush and a mixture of water and a pH-neutral deck cleaner can be used. Always test any cleaning product on an inconspicuous area first to ensure it does not stain or damage the wood. Rinse the deck thoroughly after cleaning to remove all detergent residue. Ensure proper ventilation beneath the deck to help with drying and prevent moisture buildup, which can contribute to mildew.

Worked Example: Annual Maintenance for a 12x16 Foot Deck

Let's consider a hypothetical 12-foot by 16-foot Cumaru deck (192 square feet) in a moderately sunny location. This example illustrates the tasks and considerations for maintaining the original color.

**Spring (Annual):** Begin with a thorough cleaning. Sweep off all debris. Use a hardwood deck cleaner following manufacturer instructions, applying with a pump sprayer or roller, letting it dwell, and then scrubbing with a stiff brush. Rinse thoroughly with a garden hose or a low-pressure washer (under 1200 PSI) to avoid damaging the wood.

**Summer (Annual):** Once dry, apply a high-quality oil-based hardwood decking finish. For a 192 square foot deck, you might need about 1 gallon of finish. Apply with a roller or brush, working with the grain. Allow adequate drying time between coats if multiple coats are recommended. Always follow the specific product instructions for application and reapplication rates.

**Fall/Winter (As needed):** Continue with routine sweeping to remove leaves and snow. If any stubborn stains appear, spot clean them promptly. For areas with significant snow, consider clearing heavy snow loads to prevent prolonged moisture exposure, though Cumaru is resistant to weather changes.

Before you order

• Decide: Do I want to maintain the original color or allow Cumaru to silver naturally?
• If maintaining color: Research and select a compatible oil-based hardwood finish.
• If silvering: Plan for routine cleaning to prevent mildew and grime buildup.
• Assess deck exposure: How much sun, shade, and foot traffic will the deck receive?
• Consider local climate: How do humidity, rain, and temperature extremes affect maintenance needs?
• Gather cleaning supplies: Soft-bristle brush, pH-neutral deck cleaner, garden hose/low-pressure washer.
• Gather finishing supplies (if oiling): Oil-based hardwood finish, rollers, brushes, rags.
• Plan for ventilation: Ensure adequate airflow beneath the deck to aid drying.
• Review manufacturer guidelines: Always consult specific product documentation for cleaning and finishing recommendations.
• Budget for time and materials: Factor in the cost of cleaning products and finishes, and the time required for application.

Confirm installation details, approved uses and warranty terms in the current instructions for the exact product and profile. Your installer should verify the substrate, structure and applicable project requirements.

Questions to help you decide

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