2x4 Cumaru Pre-Grooved Decking board profile diagram
Decking

2x4 Cumaru Pre-Grooved Decking

This 2x4 Cumaru decking board (Pre-Grooved profile) pairs the proven outdoor performance of Cumaru (Brazilian Teak) with a 3,330 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 2x4 Cumaru decking boards online or call 1-844-674-4455 for expert guidance.

2 x 4(1.5"×3.5" actual)[38.1mm × 88.9mm]
Contractor Trusted
Expert Backed
Ships Nationwide
SKU: CUMA-2X4-PG-SB-L1

Configure Your Order

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

Durable, Strong, and Weather-Resistant for Long-Lasting Deck Structures

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:2.55 lbs/LF
1' board:2.5 lbs

2x4 Cumaru Pregrooved Decking — Complete Guide

Everything you need to know about pregrooved cumaru decking

About 2x4 Cumaru Pre-Grooved Decking

Cumaru lumber, known for its exceptional strength and durability, makes an ideal choice for decking applications. This 2x4 pregrooved profile not only enhances the aesthetic appeal of any outdoor space but also simplifies the installation process, allowing for a robust and elegant deck that withstands the elements. With its impressive performance in outdoor environments, Cumaru is a leading choice among contractors and builders.

  • Strength and durability work well for high-traffic areas
  • Natural resistance to moisture and insects
  • Pregrooved profile eases fastening and improves aesthetics
  • Stable in extreme weather conditions

Key Benefits

Strength and Hardness

Cumaru boasts a Janka hardness rating of 3330, making it one of the hardest domestic decking materials available, suitable for even the most demanding environments.

Natural Resistance

This wood species resists rot and insect damage, ensuring that your deck remains structurally sound for years to come.

Low Maintenance

Cumaru requires minimal maintenance compared to other woods, thanks to its natural oils that protect against moisture and decay.

Aesthetic Appeal

The pregrooved profile enhances the natural beauty of the wood while ensuring a cleaner look with hidden fasteners.

Technical Specifications

Janka Hardness

3330

Density

65 lbs/ft³

Durability Rating

Class 1 (very durable)

Dimensional Stability

Excellent moisture resistance and stability against warping

Installation Guide

Difficulty:
Moderate

Key Tips:

  • Ensure proper ventilation under the deck for airflow
  • Leave appropriate expansion gaps between boards
  • Use high-quality stainless steel screws for fastening

Recommended Tools:

Drill with a countersink bit
Measuring tape
Circular saw

Maintenance & Care

Cleaning

Regularly sweep debris off the deck and wash with mild soap and water to prevent buildup.

Finishing

Consider applying a penetrating oil to maintain color and reduce graying from UV exposure when necessary.

Weathering

With proper care, Cumaru will weather gracefully without significant degradation over time.

2x4 Cumaru Pre-Grooved Decking — Frequently Asked Questions

A 2x4 Cumaru board weighs approximately 2.55 lbs per linear foot. Cumaru has a density of about 68 lbs/ft³, making it one of the densest commercially available hardwoods. A 12-foot 2x4 Cumaru board weighs approximately 30 lbs. Always factor weight into your structural and shipping calculations.

2x4 Cumaru decking has an expected service life of up to 50+ years when properly installed. This is 3-5× longer than pressure-treated pine and 2-3× longer than cedar. Cumaru achieves this exceptional longevity through its 3,330 Janka hardness and Class 1 durability rating, providing built-in resistance to rot, decay, insects, and fungal growth without chemical preservatives.

2x4 Cumaru decking pricing varies by profile, grade, and board length. Select and Better grade boards typically range from $4-$12 per linear foot before shipping. While the upfront cost is higher than pressure-treated lumber, Cumaru's up to 50+-year service life makes the lifetime cost per year significantly lower. Use the configurator above for exact pricing, or request a custom quote for large orders.

Yes — 2x4 Cumaru wood decking outperforms composite in hardness (3,330 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 wood decking costs less over its much longer lifetime. Composites do offer lower upfront maintenance, but Cumaru's natural beauty and durability make it the superior long-term investment.

Cumaru is widely considered one of the best woods for 2x4 decking boards. With a 3,330 Janka hardness rating, Class A fire-rated certification, and up to 50+-year lifespan, Cumaru (Brazilian Teak) outperforms nearly every other commercially available wood species. Other excellent options include Cumaru (Brazilian Teak) and Massaranduba (Brazilian Redwood), but Cumaru remains the industry benchmark for premium outdoor hardwood applications.

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 2x4 Cumaru board has actual finished dimensions of 1.5" × 3.5" (38.1 x 88.9 mm). The "2x4" 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 (1.5" × 3.5") 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

2x4 Cumaru Pregrooved Decking — Complete Buyer's Guide

Cumaru, also known as Brazilian Teak, is a premium tropical hardwood sourced from Amazon Basin, northern South America (Brazil, Venezuela, Guyana). With a Janka hardness rating of 3,330 lbf and a density of 65 lbs/ft³, Cumaru is classified as Class 1 - Very Durable — one of the most durable commercial lumber species available. The heartwood exhibits light to medium brown with reddish tones with interlocked grain, medium to coarse texture, creating a striking natural appearance that improves with age.

Why Choose 2x4 Cumaru Wood for Your Deck?

Cumaru decking delivers a naturally slip-resistant, splinter-free surface that stays cool underfoot even in direct sunlight. Unlike composite or pressure-treated alternatives, it never fades to a dull gray unless you want the natural silver patina look. Properly installed 2x4 Cumaru decking delivers a service life of 50+ years with minimal maintenance — an optional annual oil treatment preserves the original color, or you can let the Cumaru wood weather to a distinguished silver-gray patina. Cumaru carries a Class A - Low flame spread, making it suitable for wildfire-prone regions where code-compliant materials are required.

The 2x4 pregrooved profile has factory-milled grooves along both edges, designed specifically for hidden fastener clip systems like Ipe Clip or DeckWise. This creates a clean, screw-free surface with no visible hardware. All Cumaru lumber is available in Select and Better grade with lengths ranging from 4′ to 20′. For detailed step-by-step instructions, consult our Cumaru installation guide. Long-term care recommendations are covered in our Cumaru maintenance guide.

2x4 Cumaru Decking — Installation & Coverage Specs

  • Recommended joist spacing: 24" on center for 2x4 boards (1.5" actual thickness)
  • Fastener placement: Hidden clip fastener in each factory-milled groove, one clip per joist
  • Board weight: A 12-foot 2x4 Cumaru board weighs approximately 30 lbs (2.48 lbs/LF)
  • Coverage: Each 12-foot 2x4 board covers 3.5 sq ft of decking surface (3.5" face width)
  • Pre-drilling required: Always pre-drill in Cumaru — the 3,330 lbf hardness prevents direct screwing

Janka Hardness

3,330 lbf

Service Life

50+ years

Durability

Very Durable

Fire Rating

Class A

2x4 Cumaru Decking — Frequently Asked Questions

2x4 Cumaru decking has an expected service life of 50+ years when properly installed and maintained. This is 3-5x longer than pressure-treated pine and 2-3x longer than cedar. Cumaru achieves this exceptional longevity through its natural density (Janka hardness: 3,330 lbf) and Class 1 durability rating, which provide built-in resistance to rot, decay, insects, and fungal growth — all without chemical preservatives.

2x4 pregrooved Cumaru boards are compatible with all major hidden fastener systems including Ipe Clip Extreme S, DeckWise Ipe Clip, and Camo EdgeClip. These stainless steel clips insert into the factory-milled grooves and secure the board to the joist from below — creating a clean surface with no visible screws. Always use 316 stainless steel clips in coastal environments.

2x4 Cumaru decking pricing varies by profile, grade, and board length. 2x4 Pregrooved boards in Select and Better grade typically range from $4-$12 per linear foot before shipping. While the upfront cost is higher than pressure-treated lumber, Cumaru's 50+ years service life makes the lifetime cost per year significantly lower. Use our online configurator above to see exact pricing for your selected options, or request a custom quote for large orders.

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