Engineered Wood Siding & Engineered Wood Trim

Engineered Wood Siding & Engineered Wood Trim

Engineered Wood Siding and Engineered Wood Trim (EWST) are categories of composite panels used for decorative surfacing that have been designed and manufactured to perform in interior and exterior exposure applications with the appearance of traditional wood. These advanced composites can be engineered with enhanced resistance to moisture, dimensional stability and protection against fungal decay and termites.

The engineered properties translate into long-lasting durability allowing for decades of service life while maintaining their attractive appearance. Todays engineered wood siding and wood trim products are highly versatile and come in many forms including sophisticated woodgrains and embossed surfaces.

Because engineered wood siding and trim are a types of composite panels made from residual wood fiber, such as chips and shavings, they are carefully value engineered for each application. This results in product solutions which are substantially less expensive than alternatives.

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engineered wood siding house

Common Uses for Engineered Wood

  • Siding
  • Interior Trim
  • Exterior Trim

engineered wood siding   engineered wood trim house   

engineered wood trim

Today's siding and trim products are offered in a wide range of textures, widths and profiles that can create endless styles and themes.

Product Standards and Certification

The American National Standard for Hardboard Siding (ANSI A135.6), now referred to as the Engineered Wood Siding Standard, covers requirements and methods of testing for exterior durability, dimensions, straightness, squareness, physical properties and surface characteristics. It also includes trade terms and methods of identifying engineered wood siding. Third-party certification to the ANSI Standards is required for many applications of siding panels. Many building code jurisdictions require the physical properties of engineered wood siding to be third-party certified. CPA’s accredited certification program is recognized and approved by building code officials to evaluate siding products for code compliance.

The ANSI Engineered Wood Trim Standard was completed in 2012.  The new standard covers requirements and methods of testing for exterior durability and interior applications including physical and mechanical properties.  This consensus-based standard is sponsored by CPA.

Recommended Reading

Available from the association bookstore:

Available for download:

  • Buyers Guide
  • Maintenance Tips for Engineered Wood Siding Technical Bulletin [PDF]


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