Sienna Plus: How a Legacy Wood Product Got a High-Tech, Eco-Friendly Upgrade

TORONTO, ON – June 25, 2026

In the world of building materials, true innovation often lies not in radical reinvention, but in the intelligent evolution of a proven solution. Timber Specialties Limited, the Canadian wood preservative division of global chemical and materials company Koppers Inc., has just unveiled a prime example with the launch of MicroPro Sienna Plus. This enhanced treated wood product builds upon the legacy of its predecessor, MicroPro Sienna, which transformed the Canadian residential lumber market over 13 years ago by replacing the ubiquitous green-hued treated wood with a warm, natural brown tone that quickly became the new industry standard.

Now, MicroPro Sienna Plus aims to set the bar even higher. It’s an incremental but significant upgrade, designed to address a key consumer pain point—colour fading—while doubling down on the environmental credentials that made the original a market leader. This launch is more than a product refresh; it’s a strategic move reflecting a deep understanding of market trends, from homeowner aesthetics to the growing demand for sustainable construction.

An Aesthetic Upgrade Backed by Science

For any homeowner or contractor who has invested in a new deck or fence, the gradual weathering of the wood from a rich brown to a muted grey is a familiar, if unwelcome, process. Timber Specialties has targeted this issue directly with MicroPro Sienna Plus. The core innovation is an enhanced colour system engineered for superior longevity.

According to the company, this new formulation was developed and validated through extensive comparative weathering evaluations spanning more than 20 seasons of exposure. The result is a product that demonstrably maintains its signature warm Sienna tone for a longer period, preserving the aesthetic appeal of outdoor living spaces with less maintenance. “With MicroPro Sienna Plus, we are strengthening a product contractors and homeowners already trust, delivering the same great preservative protection plus enhanced colour performance,” said Jana Proctor, Marketing Manager at Timber Specialties.

This focus on lasting aesthetics resonates deeply with market demands. As outdoor areas increasingly function as extensions of indoor living spaces, visual appeal and long-term value are paramount. By extending the life of the wood's colour, Sienna Plus helps protect a homeowner's investment and reduces the impetus for premature replacement or frequent re-staining.

Beyond the colour, the product retains the high-performance characteristics that made the original a trusted name. It continues to offer robust protection against fungal decay and termite damage, a critical feature for any exterior wood. Furthermore, its chemistry results in corrosion rates on metal fasteners and hardware that are comparable to untreated wood, a significant advantage over many older treatment technologies. This formulation is also approved for direct contact with aluminum in above-ground applications, providing builders and DIYers with greater design flexibility and material compatibility.

Redefining Sustainable Wood Preservation

While the visual enhancement is the most marketable new feature, the enduring story of MicroPro Sienna—and now its 'Plus' version—is its environmental leadership. The product line was the first, and remains the only, wood treatment process to be certified as an Environmentally Preferable Product (EPP) by the independent certification body SCS Global Services. This isn't a simple marketing claim; it's a distinction based on a comprehensive Life Cycle Assessment (LCA) compliant with rigorous ISO international standards, which evaluates a product's environmental impact from cradle to grave.

The technology at the heart of this is micronized copper azole (MCA). Unlike traditional treatments that dissolve copper in chemical solvents, the MCA process grinds copper into microscopic particles and forces them directly into the wood's cells without the use of industrial solvents. This has several profound environmental benefits.

First, the preservative is made from 100% recycled copper, contributing to a circular economy. Second, the solvent-free process results in a product with very low volatile organic compound (VOC) emissions, earning it the UL GREENGUARD GOLD certification. This certification signifies that the product is suitable for use in sensitive environments like schools and healthcare facilities.

Most importantly, the micronization process creates an incredibly strong bond between the preservative and the wood fibers. This results in minimal leaching of copper into the surrounding environment. Independent research has shown that MicroPro treated wood products release 90% to 99% less copper into aquatic and terrestrial environments compared to many standard copper-based treated wood products. This dramatically reduces its environmental footprint, a critical factor as regulators and consumers alike demand more responsible building materials.

A Strategic Move to Solidify Market Leadership

The launch of MicroPro Sienna Plus is a calculated business maneuver designed to reinforce market dominance. When the original Sienna product entered the market, it successfully capitalized on and accelerated a consumer shift toward brown-toned wood. This update serves to protect that leadership position by addressing the next logical frontier in product performance: colour retention.

The strategy is amplified by a powerful partnership with Doman Building Materials Group Ltd., one of North America’s largest producers and distributors of pressure-treated wood. Doman's vast retail network ensures that MicroPro Sienna Plus is immediately available to a broad customer base across Canada, appearing on the shelves of major building suppliers like RONA, Home Hardware, Castle, and Timber Mart.

“We are proud of the reputation MicroPro Sienna has earned in the Canadian market,” stated Stephen Marshall, VP of Treated Wood at Doman. “MicroPro Sienna Plus builds on that strong foundation, positioning the brand for continued growth across Canadian retailers.” This statement underscores the symbiotic relationship: Timber Specialties provides the innovative technology, and Doman provides the production capacity and market access to make it a commercial success.

This launch also aligns with Doman’s broader growth ambitions. The company's recent acquisitions of pressure-treating plants in the United States signal a clear intent to expand its footprint in the treated wood sector. By continuously improving its flagship product offering in Canada, the partnership ensures it remains at the forefront of the industry, ready to meet evolving demands with a technologically advanced and environmentally sound solution.

Ultimately, the introduction of MicroPro Sienna Plus is a case study in modern product stewardship. It demonstrates how a company can listen to its market, invest in targeted R&D, and leverage a strong distribution partnership to deliver a product that is not only better for the end-user but also better for the environment. By enhancing an already successful product with tangible aesthetic and performance benefits while reinforcing its best-in-class sustainability profile, Timber Specialties has set a new benchmark for the future of residential treated wood.