1x6 Cumaru Pre-Grooved Decking board profile diagram
Decking

1x6 Cumaru Pre-Grooved Decking

This 1x6 Cumaru Pre-Grooved decking board pairs the proven outdoor performance of Cumaru (Brazilian Teak) with a 3,540 Janka hardness rating — one of the hardest commercially available woods on earth. The pre-grooved profile accepts hidden clip fastening systems like Ipe Clip®, delivering a clean, screw-free surface ideal for exterior decks, patios, and pool surrounds. In stock and ships nationwide — order Cumaru decking online or call 1-844-674-4455 for expert guidance.

1 x 6(0.75"×5.5" actual)[19.0mm × 139.7mm]
Contractor Trusted
Expert Backed
Ships Nationwide
SKU: CUMA-1X6-PG-SB-L1

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Select profile, grade, and length below to see live pricing

Exceptional Strength and Durability for Your Decking Needs

Pregrooved

Grooves on both edges for field boards

Select and Better is our standard grade

Length Guide

Available lengths: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22′

Estimated Shipping Weight
Weight per linear foot:2.01 lbs/LF
1' board:2 lbs

1x6 Cumaru Pre-Grooved Decking — Complete Guide

Everything you need to know about pregrooved cumaru decking

About 1x6 Cumaru Pre-Grooved Decking

Cumaru lumber is an ideal choice for decking applications due to its remarkable strength, durability, and natural resistance to the elements. With its pre-grooved profile, Cumaru decking not only enhances the aesthetic appeal of outdoor spaces but also simplifies the installation process, making it a preferred option for both contractors and DIY enthusiasts.

  • Exceptional strength and weather resistance
  • Pre-grooved profile for easy installation
  • Natural resistance to rot and insects
  • Aesthetic appeal with varied grain patterns and coloration

Key Benefits

Strength and Durability

Cumaru is highly rated for its strength and is less prone to warping, cracking, and splintering compared to many other woods, ensuring a long-lasting deck.

Weather Resistance

Resistance to the elements ensures that Cumaru can withstand harsh climates, including moisture and ultraviolet exposure, making it ideal for outdoor use.

Aesthetic Appeal

The unique grain patterns and rich color variations of Cumaru add visual interest to decks, enhancing outdoor living areas.

Low Maintenance Requirements

Once installed, Cumaru decking requires minimal maintenance, saving time and effort for homeowners and contractors alike.

Technical Specifications

Janka Hardness

3330

Density

over 60 lbs/ft³

Durability Rating

Class 1 (Very Durable)

Dimensional Stability

Highly stable with minimal movement on drying and moisture exposure

Installation Guide

Difficulty:
Moderate

Key Tips:

  • Use concealed fasteners compatible with pre-grooved profiles
  • Ensure proper expansion spacing between boards to account for wood movement
  • Ventilate underneath the deck to prevent moisture buildup

Recommended Tools:

Drill with screwdriver bits
Table saw for cuts
Measuring tape

Maintenance & Care

Cleaning

Regularly sweep the deck and clean with a mild detergent and brush to prevent dirt build-up.

Finishing

Consider applying a UV protective sealant to maintain color and protect against sun damage.

Weathering

Cumaru may develop a silver patina over time if not treated, which is a natural characteristic of the wood.

Frequently Asked Questions

A 1x6 Cumaru board weighs approximately 2.01 lbs per linear foot. Cumaru has a density of about 68 lbs/ft³, making it one of the densest commercially available hardwoods. Always factor weight into your structural and shipping calculations.

Yes — Cumaru is rated Durability Class 1 (Very Durable) and is naturally resistant to rot, decay, insects, and fungal attack without chemical treatment. It is Class B fire-rated and performs exceptionally well in full exterior exposure including decking applications. While ground contact is possible, we recommend elevating Cumaru boards at least 6" above grade for maximum lifespan.

Cumaru outperforms composite in hardness (3,540 vs ~200 Janka), lifespan (up to 50+ years vs 25-30 years), and heat resistance. Unlike composites, Cumaru won't melt, warp in extreme heat, or fade significantly. While initial cost is similar ($8-15/LF installed), Cumaru costs less over its much longer lifetime. Composites do offer lower upfront maintenance.

Cumaru requires minimal maintenance. Without treatment, it naturally weathers to an elegant silver-gray patina over 6-12 months. To maintain the original warm brown color, apply a UV-inhibiting penetrating oil (like Ipe Oil or Penofin) once or twice annually. Cleaning involves periodic washing with a mild soap solution. No sanding, staining, or sealing is required for structural durability.

Cumaru is DIY-friendly with proper preparation. Key requirements: (1) Always pre-drill all screw holes — Cumaru is too hard for direct screwing. (2) Use only 305 or 316 stainless steel fasteners — standard hardware will corrode and stain. (3) This pre-grooved profile uses hidden clip systems like Ipe Clip® for a screw-free surface. (4) Allow boards to acclimate on-site for 5-7 days before installation. A compound miter saw with a carbide-tipped blade is recommended.

A nominal 1x6 Cumaru board has actual finished dimensions of 0.75" × 5.5" (19.0 x 139.7 mm). The "1x6" is the nominal (rough-cut) size — after kiln drying and precision surfacing, all hardwood lumber finishes slightly smaller. This is standard across the lumber industry, similar to how a nominal 2×4 softwood measures 1.5" × 3.5". Always use the actual dimensions (0.75" × 5.5") when calculating material quantities and coverage for your project.

We responsibly, legally, and ethically source all our Cumaru. We work only with suppliers who follow responsible forestry practices with full chain-of-custody transparency. Note: We are not FSC certified. Cumaru trees grow naturally in diverse tropical forests and regenerate well under managed harvest. The extremely long lifespan (up to 50+ years) means fewer replacements compared to softwood or composite alternatives, reducing long-term environmental impact.

Shipping & Delivery

Nationwide delivery: We ship to all 50 states via LTL freight, flatbed, or terminal pickup

Typical lead time: 5-10 business days for standard orders (custom milling may add 2-3 weeks)

Shipping estimate: Final freight cost calculated at checkout based on your location and order size

Rush service available: Contact us for expedited milling and shipping options

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