Contractor's Guide to Specifying Massaranduba

Brazilian Redwood: Intense Density and Color

Massaranduba (Manilkara bidentata) is an incredibly dense, deep red tropical hardwood. It rivals Ipe in weight and hardness, offering exceptional longevity, but requires careful specification and installation due to its movement characteristics.

Physical & Mechanical Properties

One of the hardest and heaviest woods in the world, Massaranduba is engineered for the most punishing environments.

Botanical NameManilkara bidentata
Janka Hardness3,190 lbf (14,200 N)
Specific Gravity0.85 (Basic), 1.08 (12% MC)
Modulus of Rupture27,280 psi (188.1 MPa)
Modulus of Elasticity3,300,000 psi (22.76 GPa)
Crushing Strength13,000 lbf/in²
ShrinkageRadial: 5.7%, Tangential: 9.4%, Volumetric: 16.8%
Fire RatingClass A (ASTM E84) dependent on testing

Architectural Implications

With an extremely high Modulus of Elasticity, Massaranduba handles immense loads without deflecting. However, its high volumetric shrinkage ratio (16.8%) means it is highly reactive to moisture changes and requires strict fastening protocols.

Grading & Appearance Expectations

Premium Grade, known for its striking, consistent coloration.

Color Variation

Heartwood is a medium to dark plum red, occasionally with a purplish hue. Highly uniform in color compared to Ipe. Will weather to a distinct silver-gray.

Grain Pattern

Straight, subtle, and uniform grain with a very fine texture. Takes a high natural polish.

Weathering

Excellent decay resistance, but highly prone to surface checking (hairline cracks) when exposed to direct sun and low humidity. This checking is cosmetic, not structural.

Installation Specifications

Acclimation & Storage

Critical: Requires 14–21 days of on-site acclimation. Proper stickering and protection from extreme elements during this phase are non-negotiable.

Cutting & Machining

Extremely difficult to work. Quickly blunts cutting edges. Carbide-tipped tooling is mandatory. Sands beautifully to a glass-like finish.

Fastening Systems

Face-screwing is strongly recommended over hidden clips, especially for 1x6 profiles, to control cupping. Pre-drilling is mandatory. Use 316 stainless steel screws.

End Sealing

Seal all cross-cuts immediately. The high shrinkage rate makes end-checking common if not sealed properly.

Ideal Applications

✓Commercial decking and boardwalks
✓Heavy-duty exterior construction
✓Rainscreen siding (using 1x4 to minimize cupping)
✓Bridges and marine applications

Limitations & Warnings

⚠High risk of cupping in wide profiles (1x6) if not properly face-screwed and ventilated.
⚠Prone to surface checking in dry, arid climates (e.g., Colorado, Utah, Nevada).
⚠Very heavy, increasing labor fatigue.