About Verified Timber
Ensuring structural timber meets its claimed strength and stiffness characteristics.
Achieve Unmatched Strength and Safety with Verified Timber
At Verified Timber, we ensure your timber meets the highest standards for strength and safety. Through strict grading, verification, and regular audits, our programme guarantees reliable, high-quality timber for all your construction needs.
Why Timber Needs Verification
In 2005, the Timber Structures Standard (NZS3603) was amended to require that timber used in certain construction applications must be verified for its strength and stiffness properties. To support this requirement, a new standard, NZS3622, was introduced, setting out the parameters for verifying these timber properties. As a result, the Verified Timber quality assurance programme was established to ensure that timber producers meet these critical standards.
Structural timber in building projects must consistently meet specific strength and stiffness standards to ensure safety and reliability. These standards are vital for maintaining the integrity of structures and are a core part of our Verified Timber programme.
How Our Verified Timber System Works
At Verified Timber Ltd, we have developed a rigorous quality assurance programme to ensure that sawmills produce structural timber that meets the requirements set by NZS3622. Companies licensed by us must adhere to a detailed Quality Manual, which outlines the procedures and practices for producing verified timber. We conduct regular audits to ensure our licensees consistently meet the programme’s requirements.
Our Grading Systems
Verified Timber can be produced using two grading systems: Machine Stress Grading (MSG) and Visual Stress Grading (VSG).
Machine Stress Grading (MSG)
Machine Stress Grading (MSG) uses machines to test the timber's stiffness, but not its strength directly. Although there is a correlation between stiffness and strength, additional visual inspections are necessary to assess the impact of knots and other visual characteristics on the timber's overall strength.
Visual Stress Grading (VSG)
Visual Stress Grading (VSG), sorts timber based on visual characteristics like knots, grain deviations, and splits, which indicate potential weaknesses affecting strength. While effective for identifying these defects, visual grading is less reliable for predicting stiffness, which measures the timber's resistance to bending.
Our Verification Process
Our verification process is a continuous quality control system where timber is randomly sampled from production and tested for both stiffness and strength using a static bending test machine.
The results are analysed statistically to ensure that the timber meets the required standards for each grade.
This process helps us maintain the integrity and quality of the timber, ensuring it meets the structural needs of various building projects.
Third-Party Audits & Compliance
To maintain the highest standards in timber production, all companies participating in our Verified Timber programme must undergo regular audits. We conduct these audits to ensure that our licensees consistently meet the stringent requirements for producing compliant, high-quality structural timber.
These regular audits provide an extra layer of assurance, verifying that all timber produced under our programme adheres to the necessary standards for strength and stiffness.
The Mark of Strength
Timber that passes all tests and meets the requirements of our programme can carry the Verified Timber trademark. This trademark is stamped on the timber, along with the producer's name or ID, the timber grade, and the grading standard used. Timber marked with the Verified Timber trademark complies with the New Zealand Standard NZS3622 for Verification of Timber Properties.
Most importantly, the Verified Timber trademark signifies that the product is licensed by Verified Timber Ltd. This means the producer follows the Verified Timber Quality Manual and is subject to our audit programme. Our programme is endorsed by the New Zealand Timber Industry Federation and is the preferred choice for its members. Only companies licensed and regularly monitored by us are authorised to use the Verified Timber trademark.
Become a Verified Timber Licensee
Verified Timber welcomes new licensees and is committed to supporting and strengthening our community.