1x6 Cumaru Rainscreen Siding board profile diagram
Siding

1x6 Cumaru Rainscreen Siding

This 1x6 Cumaru siding board (Rainscreen profile) offers unmatched exterior cladding longevity, backed by Cumaru's 3,330 Janka hardness and a natural lifespan of up to 50+ years. The rainscreen profile is designed for ventilated clip systems, allowing airflow behind the cladding for superior moisture management on exterior cladding and accent walls. In stock and ships nationwide — order 1x6 Cumaru siding boards 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-RAIN-SB-L1

Configure Your Order

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

Ideal for Sustainable Siding and Cladding Solutions

Rainscreen

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:2.0 lbs

1x6 Cumaru Rainscreen Siding — Complete Guide

Everything you need to know about rainscreen cumaru siding

About 1x6 Cumaru Rainscreen Siding

Cumaru lumber stands out as an exceptional choice for exterior siding and cladding applications due to its robust dimensional stability and inherent weather resistance. This tropical hardwood, native to South America, excels in harsh climates, making it suitable for various environmental conditions. The rainscreen profile not only enhances aesthetic appeal through attractive shadow lines but also allows for effective moisture management and improved ventilation, thereby prolonging the life of the siding. When installed correctly, this profile offers a modern look while ensuring the functionality necessary for a durable exterior surface.

  • Superior dimensional stability minimizes warping and cracking.
  • Natural resistance to weathering extends lifespan in outdoor settings.
  • Rainscreen profile enhances visual depth and shadow lines.
  • Effective moisture management due to ventilated construction.

Key Benefits

Durability Against Elements

Cumaru's high resistance to rot and insects ensures that your siding will withstand the challenges of outdoor exposure, protecting your investment over time.

Visual Appeal

The natural grain patterns and rich color variations of Cumaru enhance the beauty of any building, whether used for residential homes or commercial facades.

Sustainable Choice

Sourced responsibly, Cumaru lumber provides an eco-friendly option for siding that meets both aesthetic and environmental needs.

Technical Specifications

Janka Hardness

3330

Density

65 lbs/ft³

Durability Rating

Class 1 (Highly Durable)

Dimensional Stability

Excellent, minimal shrinkage and swelling in changing environments

Installation Guide

Difficulty:
Moderate

Key Tips:

  • Ensure proper ventilation behind the rainscreen profile to prevent moisture buildup.
  • Leave appropriate expansion gaps between boards to allow for natural movement.
  • Align boards carefully to maintain consistent shadow lines.

Recommended Tools:

Clips for hidden fastening
Circular saw or miter saw
Drill with suitable wood screws

Maintenance & Care

Cleaning

For routine maintenance, clean with a mild soap solution and a soft brush to remove dirt and debris without harming the surface.

Finishing

To maintain color and protect against UV damage, apply a suitable exterior finish as per manufacturer guidelines annually.

Weathering

Over time, Cumaru will weather to a silvery patina, which can be preserved by periodic cleaning and finishing.

1x6 Cumaru Rainscreen Siding — 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. A 12-foot 1x6 Cumaru board weighs approximately 23 lbs. Always factor weight into your structural and shipping calculations.

1x6 Cumaru siding 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.

1x6 Cumaru siding 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 — 1x6 Cumaru wood siding 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 1x6 siding 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) Face-screw with stainless steel trim-head screws. (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

Alternative Siding Option

This same Cumaru 1 x 6 is also available in a different siding profile:

Shiplap

Overlapping profile for traditional siding applications

1x6 Cumaru Rainscreen Siding — 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 1x6 Cumaru Wood for Your Siding?

As exterior cladding, Cumaru siding provides a weather-tight barrier with exceptional impact resistance. The dense grain resists dents, hail damage, and woodpecker damage far better than cedar, pine, or fiber cement alternatives. Properly installed 1x6 Cumaru siding 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 1x6 rainscreen profile is engineered for open-joint cladding systems with ventilation gaps behind the boards. This modern system manages moisture while creating a striking contemporary facade. 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.

1x6 Cumaru Siding — Installation & Coverage Specs

  • Recommended joist spacing: 16" on center for 1x6 boards (0.75" actual thickness)
  • Fastener placement: Secure per profile requirements, one fastener per joist minimum
  • Board weight: A 12-foot 1x6 Cumaru board weighs approximately 23 lbs (1.95 lbs/LF)
  • Coverage: Each 12-foot 1x6 board covers 5.5 sq ft of siding surface (5.5" 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

1x6 Cumaru Siding — Frequently Asked Questions

1x6 Cumaru siding 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.

Use 305 or 316 stainless steel screws for all Cumaru installations — never use galvanized or coated deck screws, which will corrode and stain the wood. Pre-drill every hole using a countersink bit sized for your screw. For 1x6 boards, place screws approximately 1" from each edge and 3/4" from board ends. A combination drill/driver with a clutch setting prevents over-driving into this extremely hard wood.

1x6 Cumaru siding pricing varies by profile, grade, and board length. 1x6 Rainscreen 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.

Related Cumaru Products & Resources

Explore more Cumaru siding options and expert guides