Getting your timbers graded is a crucial step in timber framing, ensuring that the lumber you use meets structural and safety standards. Building codes and insurance companies often require graded timbers, and they provide assurance of the wood's quality and strength. Here's how to navigate the process and find additional resources to help you.
Why Timber Grading is Important
- Safety Assurance: Graded timber has been evaluated for structural integrity, reducing the risk of failures in your construction.
- Compliance: Building codes often require graded lumber to meet regional or national standards.
- Insurance and Resale Value: Proper grading can affect insurance premiums and increase the property's value.
Types of Timber Grading
- Visual Grading: Inspectors assess lumber based on visible characteristics such as knots, splits, grain slope, and other defects.
- Machine Stress-Rated (MSR) Grading: Machines use non-destructive testing methods to evaluate lumber's strength and stiffness.
Steps to Get Your Timbers Graded
- Understand Local Requirements: Consult your local building authority to determine the specific grading requirements for your project.
- Choose a Grading Agency: Select an accredited agency or certified inspector recognized by organizations like the American Lumber Standard Committee (ALSC) or the Canadian Lumber Standards Accreditation Board (CLSAB).
- Prepare Your Lumber: Ensure your timbers are properly milled and free from excessive defects that could affect grading.
- Schedule an Inspection: Arrange for an on-site inspection if necessary. Some agencies offer transient lumber inspection services for smaller quantities.
- Receive the Grade Stamp: Once inspected, your lumber will be stamped with the appropriate grade, certifying its compliance with standards.
Finding Grading Services
- Transient Lumber Inspection Services: Companies like Timber Products Inspection offer services where inspectors come to your location to grade lumber that isn't part of a larger mill operation.
- Regional Grading Agencies: Organizations such as the Northeastern Lumber Manufacturers Association (NELMA) or the Pacific Lumber Inspection Bureau (PLIB) provide resources and can connect you with certified graders.
- Consulting Foresters and Independent Inspectors: They can offer personalized services especially useful for custom or small-scale projects.
Additional Online Resources
- American Lumber Standard Committee (ALSC)
- www.alsc.org
- Provides information on grading rules and a list of accredited agencies.
- Western Wood Products Association (WWPA)
- www.wwpa.org
- Offers grading services and educational materials.
- National Hardwood Lumber Association (NHLA)
- www.nhla.com
- Specializes in hardwood grading and provides a network of certified inspectors.
- Canadian Lumber Standards Accreditation Board (CLSAB)
- www.clsab.ca
- For projects in Canada, it provides grading information and accreditation agencies.
Key Considerations
- Cost: Grading services come at a cost, which can vary based on the volume of lumber and the agency. Obtain multiple quotes to find a competitive rate.
- Documentation: Keep all grading certificates and documentation for your records, inspections, and potential future transactions.
- Moisture Content: Ensure your timber has the appropriate moisture content, as this can affect both the grading process and the structural performance of the wood.
- Species and Grade Compatibility: Different wood species have different strength properties. Ensure the species you're using suits your project's requirements.
Tips for a Smooth Grading Process
- Plan Ahead: Incorporate the grading process into your project timeline to avoid delays.
- Educate Yourself: Familiarize yourself with the grading rules applicable to your lumber species and intended use.
- Proper Storage: Store your lumber correctly before and after grading to maintain quality.
Conclusion
Getting your timber graded doesn't have to be a daunting task. By understanding the requirements, preparing adequately, and utilizing the resources available, you can ensure your timber framing project is built on a solid foundation of quality and compliance.
