1x6 Cumaru Shiplap Soffit board profile diagram
Soffit

1x6 Cumaru Shiplap Soffit

This 1x6 Cumaru soffit board (Shiplap profile) combines the rich grain of Cumaru (Brazilian Teak) with 3,330 Janka hardness, making it ideal for exposed eave linings and covered ceilings that endure for decades. The overlapping shiplap profile sheds water naturally and creates a classic, weather-resistant look for eave linings, ceilings, and covered areas. In stock and ships nationwide — order 1x6 Cumaru soffit boards online or call 1-844-674-4455 for expert guidance.

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

Configure Your Order

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

Durable, Moisture Resistant, and Visually Stunning

Shiplap

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 Shiplap Soffit — Complete Guide

Everything you need to know about shiplap cumaru soffit

About 1x6 Cumaru Shiplap Soffit

Cumaru lumber is an ideal choice for soffit applications due to its exceptional dimensional stability, durability, and moisture resistance. The shiplap profile enhances the aesthetics of any project while ensuring compatibility for ventilation needs and providing families with a clean, attractive finish. Designed to withstand various environmental factors, Cumaru offers long-lasting performance for exterior overhead uses.

  • Exceptional dimensional stability for overhead applications
  • Durable and resistant to moisture exposure
  • Elevates ventilation compatibility with its shiplap profile
  • Aesthetically pleasing, providing clean lines and a modern look

Key Benefits

High Durability

Cumaru is one of the toughest hardwoods available, making it ideal for areas exposed to the elements.

Low Maintenance

The natural oils in Cumaru provide resistance to rot and insects, requiring minimal upkeep once installed.

Aesthetic Versatility

Its rich coloration and unique grain patterns enhance any architectural style.

Technical Specifications

Janka Hardness

3330

Density

65 lbs/ft³

Durability Rating

Class 1 (very durable)

Dimensional Stability

Excellent stability under temperature and humidity changes

Installation Guide

Difficulty:
Moderate

Key Tips:

  • Ensure proper spacing for expansion.
  • Utilize stainless steel fasteners to prevent rust.
  • Leave gaps for ventilation as needed.

Recommended Tools:

Circular saw
Drill/driver
Measuring tape
Level

Maintenance & Care

Cleaning

Regularly clean with a mild detergent and water to maintain appearance.

Finishing

Apply a UV-protective finish to maintain color and extend lifespan.

Weathering

Expect some color change over time as the wood weathers, but this does not affect its integrity.

1x6 Cumaru Shiplap Soffit — 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 soffit 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 soffit 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 soffit 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 soffit 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

1x6 Cumaru Shiplap Soffit — 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 Soffit?

Cumaru soffit and porch ceiling boards create a warm, premium overhead aesthetic that vinyl and aluminum simply cannot replicate. The natural grain pattern adds architectural character to any covered outdoor space. Properly installed 1x6 Cumaru soffit 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 shiplap profile creates an overlapping joint with a distinctive shadow line between boards. Popular for siding, accent walls, and architectural cladding applications. 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 Soffit — 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 soffit 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 Soffit — Frequently Asked Questions

1x6 Cumaru soffit 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 soffit pricing varies by profile, grade, and board length. 1x6 Shiplap 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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