Description
Engineered for Low-Airflow Designs & Moisture Management
The Cumaru 1×6 Bottom-Grooved Decking Board (actual ¾″ × 5½″) is designed for builds where airflow underneath the deck surface is limited. The underside relief grooves help promote more balanced moisture exchange, reducing the likelihood of cupping in environments such as roof membranes, over-slab patios, and low-clearance substructures. This makes the bottom-grooved profile a smart upgrade when your framing design leaves minimal room for ventilation.
Cumaru’s natural density provides excellent rot resistance, insect resistance, slip resistance, and long-term durability. With its warm red-gold color range and interlocked grain, this profile delivers both high performance and refined visual appeal in demanding outdoor environments.
When to Choose the Bottom-Grooved Cumaru Profile
Select this profile when you need added protection against trapped humidity below the deck surface. Bottom-grooved Cumaru is recommended for:
- Rooftop decks built over waterproofing membranes
- Decks installed directly above concrete pads
- Projects with 4–8 inches of clearance beneath the framing
- Walkways and platforms where airflow is naturally limited
For broader species details—including color variation, grain structure, and weathering behavior—explore the
Cumaru Decking Page.
Hidden Fastening, Compatibility & Installation Support
Bottom-grooved boards pair best with solid or single-grooved Cumaru boards in the main field. This allows builders to use hidden clip systems where needed, while still benefiting from the underside relief grooves in low-ventilation locations. For step-by-step guidance on hidden fastener installation methods, consult the:
To better understand airflow requirements, drainage planning, and moisture behavior in Brazilian hardwoods, review
Ipe & Hardwoods: Drainage & Cupping.
Sustainability & Responsible Forestry Practices
All Cumaru stocked by Brazilian Wood Depot is sourced through responsibly managed forest operations that follow strict harvesting controls for long-term ecological health. To learn how sustainable hardwood sourcing protects tropical forests, explore the
Sustainable Ipe Certified Course.
Get An Accurate Quote!
Get a fast, accurate quote on premium Brazilian hardwoods like Ipe, Cumaru, and Tigerwood—delivered nationwide from our Atlanta lumberyard. We’ll review your project details and get back to you quickly with current pricing, shipping options, and expert material guidance.
Bundle & Save on Complete Deck Systems
Pair your bottom-grooved Cumaru boards with Heritage Premium Deck Framing for improved structural performance, reduced movement, and long-term reliability. Combine your lumber, framing, and hardware in a single shipment for the most efficient pricing and delivery.
Nationwide Shipping Excellence
Brazilian Wood Depot ships Cumaru nationwide using fully protected crating with a damage-free delivery focus. Orders include prep photos, GPS tracking, and transparent communication from pickup to arrival. Learn more in the
Shipping Guide.
Plan, Compare & Explore Cumaru Decking
See how Cumaru performs in actual installations by browsing the
Cumaru Decking Photo Gallery.
Use the Decking Wizard to compare fasteners, profiles, and design conditions for your project.
