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Specialty Lumber

U.S. LUMBER offers unparalleled quality and craftsmanship with our specialty lumber collection. From exquisite hardwoods to durable exotic woods, our selection offers the finest materials to elevate your projects, ensuring beauty and longevity in every piece.

*Product mix varies by location, please check with your local branch for product availability.

Solarwood

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Solarwood

SOLARWOOD™ is a sustainable wood solution enhanced through the thermal modification process without the use of chemicals. This process uses heat and steam to remove sugars and moisture-bonding sites, eliminating the need for chemicals while creating durable, dimensionally stable, rich-colored wood.

Available in Poplar, Ash, Southern Yellow Pine, & Nordic Knotty, SOLARWOOD™ resists weather-related decay, making it ideal for siding, decking, millwork, and other exterior uses, while also fitting beautifully into interior applications.

With minimal upkeep and long service life, SOLARWOOD™ is manufactured in the USA and offers a greener, high-performing alternative to chemical treated wood and synthetic plastic products as well tropical hardwood like teak and ipe.

About Species

Description

  • ASH: Thermally Modified Ash is an exceptionally durable and versatile species, ideal for high-traffic applications such as decking, porch flooring, siding, and trim. With a Class 1 durability rating and a striking natural grain pattern, it delivers a rare balance of performance and visual appeal, combining the warmth of hardwood with enhanced resilience for both exterior and interior use.
  • POPLAR:Thermally Modified Poplar is an ideal choice for siding, trim, and millwork, offering a clean, consistent appearance with enhanced performance. As a hardwood, it resists grain raise and provides a refined, tight grain aesthetic suited to both modern and traditional designs with long lengths available. The thermal modification process increases dimensional stability, reducing warping, cupping, and joint separation while deepening the wood’s natural color for a rich, uniform finish throughout.
  • SOUTHERN YELLOW PINE: Thermally Modified Southern Yellow Pine delivers a strong combination of durability, stability, and value, making it an excellent choice for siding and porch flooring applications. The thermal modification process enhances resistance to moisture and decay while improving dimensional stability, reducing warping, cupping, and movement for tighter, longer-lasting installations. Its warm tones and familiar grain pattern provide a classic aesthetic suited to both traditional and modern designs. Cost-effective and sustainably sourced, it is modified without chemicals and offers easy machining and installation for precise profiles. While not recommended for decking, it excels in siding and covered porch
  • NORDIC KNOTTY: Thermally Modified Nordic Knotty offers a distinctive blend of knotty, rustic character, long lengths, and high-performance durability, making an excellent choice for siding, soffits, ceilings, decking, and interior wall applications. Proven globally, the thermal modification process enhances stability and resistance to moisture, decay, and movement while preserving the natural charm of knots and grain variation, creating a warm, organic aesthetic suited to both modern and traditional designs.

Product Details

Features & Benefits

  • THERMAL MODIFICATION:SOLARWOOD™ (thermally modified wood) Hardwoods are suitable for interior and exterior applications without the need for additional chemical preservatives. Our thermal modification processes enhance our North American Hardwood’s aesthetic and performance properties, caramelizing the material to warm brown through-body tones while significantly improving durability and dimensional stability.
  • DURABILITY: SOLARWOOD™ Thermally Modified White Ash is classified as durability class 1 “very durable”, while Thermally Modified Yellow Poplar is classified as durability class 2-3 “durable-moderately durable”. Durability is consistent throughout the piece regardless of cutting or machining.
  • DIMENSIONAL STABILITY:The lowered equilibrium moisture content of TMT Hardwoods increases their dimensional stability, allowing the material to retain its shape far better than untreated wood. This outstanding dimensional stability allows SOLARWOOD™ products to be successfully used in all climates and environmental conditions, indoors and outdoors.
  • NON-TOXIC: SOLARWOOD™ Hardwoods are pure organic material produced using only natural methods-heat and steam-without additional chemicals.
  • INSTALLATION:For installation information please refer to the SOLARWOOD™ Installation Guide. As with most hardwood cladding products, pre-drilling and high quality stainless steelscrews will be paramount for best project outcomes.
  • USE CLASS: SOLARWOOD™ Hardwood products are suitable for Use Class 3 applications, “situations in which the wood is above ground and exposed to the weather (particularly rain)” including cladding façade, rainscreen, decking and many other exterior applications. TMT Hardwoods are not recommended for use in direct ground contact applications.
  • MAINTENANCE: SOLARWOOD™ Hardwoods are durable and do not require maintenance, however, regular inspection and cleaning with fresh water and a soft bristle brush will help prevent and/or diagnose possible staining or other visual anomalies. Any applied surface coatings should be maintained in alignment with manufacturer recommendations
  • WASTE DISPOSAL:SOLARWOOD™ Hardwood off-cuts can be disposed of in the same manner as untreated wood, including burning.
  • LEACHING:Minor release of the material’s natural color pigment is possible during heavy rains early inthe product’s lifecycle and in humid spaces like saunas and spas.
  • HANDLING:Extra care must be taken during handling and installation to maintain the aesthetic consistency of the boards. Sorting and transfer should be done with support from both ends or the middle. If visible dents or scratches develop during handling, the through-body color modification allows surfaces to be sanded exposing fresh, tonally comparable wood.
  • FIRE RATING: SOLARWOOD™ Hardwood products are fire rated to Class B, in accordance with ASTM E84.
  • ACOUSTIC PROPERTIES: SOLARWOOD™ Hardwood walls, ceilings, floors, and other interior elements naturally dampen noise acting as soft, echo-reducing breaks in the space. The porous wood surface does not reflect sound in the same way as harder and artificial materials. The use of battens or Solarwood 3D profiles will further reduce ambient noise potential in the space.
  • MACHINEABILITY: Processing will not affect the performance properties of SOLARWOOD™ Hardwoods as the modification occurs through-body. Cut or machine using best practices for dense hardwoods, including sharp tooling and use of PPE.

Solarwood Features Benefits Overview

Ash Product Overview

Knotty Rustic Product Overview

Poplar Product Overview

Southern Yellow Pine Product Overview

Technical Data Sheet

Porch Cladding Installation Points

Porch Decking Installation Points

Porch Flooring Installation Points

Decking Clear Ash Product Sheet

Decking Knotty Pine Product Sheet