1x4 Cumaru Pre-Grooved Decking board profile diagram
Decking

1x4 Cumaru Pre-Grooved Decking

This 1x4 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 1x4 Cumaru decking boards online or call 1-844-674-4455 for expert guidance.

1 x 4(0.75"×3.5" actual)[19.0mm × 88.9mm]
Contractor Trusted
Expert Backed
Ships Nationwide
SKU: CUMA-1X4-PG-SB-L1

Configure Your Order

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

Perfect for durable, low-maintenance outdoor spaces

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:1.28 lbs/LF
1' board:1.3 lbs

1x4 Cumaru Pregrooved Decking — Complete Guide

Everything you need to know about pregrooved cumaru decking

About 1x4 Cumaru Pre-Grooved Decking

Cumaru lumber is a premier choice for decking applications due to its exceptional strength, durability, and natural weather resistance. This beautiful, dense wood is ideal for outdoor environments, making it a reliable material for decks that withstand the elements. The pre-grooved profile of the 1x4 Cumaru boards not only enhances the aesthetic appeal but also simplifies installation by accommodating hidden fasteners, creating a clean and seamless look.

  • High strength and durability for long-lasting decks
  • Natural resistance to rot, decay, and insects
  • Pre-grooved profile simplifies fastening and enhances appearance
  • Rich color and grain variations add natural beauty to outdoor spaces

Key Benefits

Unmatched Durability

Cumaru's high Janka hardness rating of 3330 means it is highly resistant to wear and heavy foot traffic, making it suitable for both residential and commercial decking applications.

Natural Weather Resistance

This species exhibits excellent resistance to moisture, insects, and fungal decay, ensuring a long lifespan for your decking even in harsh conditions.

Aesthetic Versatility

With beautiful color variations and a unique grain pattern, Cumaru enhances the visual appeal of any outdoor space while remaining functional.

Technical Specifications

Janka Hardness

3330

Density

65 lbs/ft³

Durability Rating

Class 1 (Very Durable)

Dimensional Stability

Highly stable under varying moisture conditions

Installation Guide

Difficulty:
Moderate

Key Tips:

  • Leave appropriate spacing between boards for expansion
  • Ensure proper ventilation beneath the deck
  • Use high-quality, compatible fasteners for the pre-grooved profile

Recommended Tools:

Drill with countersink bits
Hidden fasteners
Measuring tape and saw

Maintenance & Care

Cleaning

Regular cleaning with a mild detergent and water is recommended to maintain the surface appearance.

Finishing

Applying a quality penetrating oil finish can enhance color and protect against UV damage.

Weathering

Cumaru naturally weathers to a beautiful gray when exposed to the elements but can maintain its rich color with proper maintenance.

1x4 Cumaru Pre-Grooved Decking — Frequently Asked Questions

A 1x4 Cumaru board weighs approximately 1.28 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 1x4 Cumaru board weighs approximately 15 lbs. Always factor weight into your structural and shipping calculations.

1x4 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.

1x4 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 — 1x4 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 1x4 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 1x4 Cumaru board has actual finished dimensions of 0.75" × 3.5" (19.0 x 88.9 mm). The "1x4" 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" × 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

1x4 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 1x4 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 1x4 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 1x4 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.

1x4 Cumaru Decking — Installation & Coverage Specs

  • Recommended joist spacing: 16" on center for 1x4 boards (0.75" actual thickness)
  • Fastener placement: Hidden clip fastener in each factory-milled groove, one clip per joist
  • Board weight: A 12-foot 1x4 Cumaru board weighs approximately 15 lbs (1.24 lbs/LF)
  • Coverage: Each 12-foot 1x4 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

1x4 Cumaru Decking — Frequently Asked Questions

1x4 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.

1x4 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.

1x4 Cumaru decking pricing varies by profile, grade, and board length. 1x4 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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