DURATAU THERMALLY MODIFIED TAUARI

DuraTau is Nova's thermally modified Tauari. Tauari, often sold as Brazilian Oak, is a medium-density South American hardwood with a fine, even texture and a straight grain. Untreated, it looks and works much like North American red oak but tests harder on the Janka scale, and it has mostly been used for flooring and interior millwork.

Thermal modification changes that. The boards are kiln dried, then heated to between 180°C and 230°C in a controlled, oxygen-free environment using only heat and steam — no chemicals, no preservatives. The process permanently alters the wood's cell structure: it absorbs far less moisture, the sugars that feed fungi and insects are converted, and the color turns a warm, uniform brown all the way through the board.

The result is a hardwood board suited to decking, siding and exterior trim, with the stability that thermally modified wood is known for and a starting density of roughly 40 lb/ft³ (640 kg/m³) — heavier than most softwoods and light hardwoods that are typically thermally modified.

DuraTau joins Ambara®, Korina and Inari™ Nordic Spruce in Nova's thermally modified line. It is a new program: initial availability is limited to two profiles, and we will expand the offering as the program develops.

Decking
The 5/4x6 S4S E4E board is a standard decking profile. Tauari's density gives it good hardness for foot traffic after modification, in the same way medium-density Korina does. Install with the ExoDek QuickClip hidden fastener to lift boards 1/8" off the joist for airflow, or face-screw with stainless fasteners.

Siding & Rainscreen Cladding
The 1x6 S4S E4E board suits open-joint rainscreen siding on the ExoClad QuickClip system, where the stability of thermally modified wood keeps joints even through seasonal humidity swings. Ask us about T&G, shiplap and other siding profiles on a project basis.

Soffit, Ceilings & Trim
The same 1x6 board works for soffit, covered porch ceilings, fascia and exterior trim where a clear, consistent hardwood look is wanted.

Fencing & Screens
A chemical-free alternative to pressure-treated lumber for privacy fences, screens and pergola infill.

Species: Tauari, Brazilian Oak (Couratari oblongifolia)
Family: Lecythidaceae
Origin: South America
Condition: Kiln dried, then thermally modified (heat and steam only, no chemicals)
Grade: FAS
Grain: Mixed grain
Profiles: 1x6 S4S E4E (19mm x 139mm) and 5/4x6 S4S E4E (25mm x 139mm)
Color: Warm medium brown throughout the board
Texture: Fine, even
Grain pattern: Even to straight
Uses: Decking, siding, rainscreen cladding, soffit, ceilings, trim, fencing

Unmodified Tauari, for reference: Janka hardness 1,650 lbf; density 640 kg/m³; modulus of rupture 12,900 psi; modulus of elasticity 1,540,000 psi; tangential shrinkage 7.3%, radial 4.2%. Thermal modification lowers density and bending strength somewhat, as it does with every species, and greatly reduces shrinkage and swelling in service. Do not use DuraTau in structural or ground-contact applications.

DuraTau installs with standard tools and standard fasteners. As with all thermally modified wood, we recommend:

Pre-drilling for face screws, since modified wood is slightly more brittle than untreated stock; Stainless steel or coated fasteners to avoid corrosion staining; Hidden fasteners where possible — ExoDek QuickClip for decking, ExoClad QuickClip for siding — so boards can move naturally; Acclimating the boards on site before installation, as thermally modified wood arrives at a lower moisture content than conventional lumber.

No finish is required for durability. Left bare, DuraTau will weather to a silver-gray like any exterior wood. To keep the brown color, apply ExoShield Wood Stain, Nova's Tung oil-based UV-protective finish, and reapply every one to three years depending on exposure. ExoWax end sealer on cut ends slows checking.

DuraTau is a new program. We are starting with two profiles and a limited quantity of inventory. If you have a decking, siding or soffit project that could use a chemical-free, stable hardwood, we would like to hear from you — contact us for current availability, pricing and samples, and tell us what profiles you would want to see next.

Related thermally modified products from Nova: