Strength grading: Timber 101 webinar 12

The Timber 101 series is a free, expert-led introduction to timber as a construction material, designed to support informed and confident decision-making across the built environment. From architects and engineers to contractors, students and DIY builders, this series is open to anyone looking to understand how timber works – and how to use it well. It is also an excellent course for foresters who wish to understand more about the material they are producing.

Across these webinars, participants will explore timber from its biological origins to its final specification and performance in buildings. Topics include tree growth and commercial species, timber structure and properties, grading and durability, moisture behaviour, and perceptions of quality.

Each webinar stands alone but together they form a comprehensive grounding in the correct selection, specification and application of timber.

Session 12: Strength grading

This Timber 101 webinar will discuss the meaning of strength grading and an explanation of the strength classes. The marking systems in use will be mentioned.

We will also explore the responsibility of the timber grader and the grading company, plus what skills are required to be a timber grader? How do you get into timber grading? Is it a career for life?

We will cover:

• Purpose of strength grading
• How strength of timber is determined – the three properties of timber called the 'grade determining properties'
• What is strength grading
• Methods of strength grading and which is better
• Types of machines in machine grading
• Strength grades and strength classes
• Dry or wet graded and Service classes
• Marking (stamps)
• Sizes and processing – can one resize structurally graded timber?
• Which timbers can we strength grade and the practicalities
• Factors affecting strength of timber
• Principles of visual strength grading
• Brief look at standards and some end-use strength grading.

Audience:

This webinar is aimed at:

• Architects, specifiers and engineers
• Forestry professionals
• Construction professionals and contractors
• Students and educators in the built environment
• DIY builders, makers and homeowners
• Anyone interested in sustainable materials and low-carbon construction

Speaker: Phil O'Leary, Director of Filros Timber Consultancy

Phil has over 25 years’ experience in timber design, specification, structural grading, supply, installation and performance. He previously led the Timber Consultancy at BM TRADA and has acted as an expert witness for over 20 years.

Speaker: Dr Andy Pitman, Principal Timber Consultant, Filros Timber Consultancy

Andy is a wood scientist with a PhD in archaeological timber conservation and a Master’s in Forest Industries Technology. He taught and supervised research for 15 years at Buckinghamshire Chilterns University College and was formerly Head of the Forest Products Research Centre.

Programme:

12.00 Welcome from Woodknowledge Wales

12.05 Introduction to series and speakers

12.10 Main presentation

13.10 Q&A session

13.25 Close and information on upcoming sessions

Registration

Attendance is free but registration is required. A Zoom link will be sent prior to the event.

NOTE: Please note that the content of this webinar is under copyright. Attendance must be live. No external recordings will be authorised or shared. Internal recording is for administrative purposes only. The use of AI bots will not be authorised and will be removed or blocked.

Timber 101 series overview

This webinar is part of the Timber 101 series designed to help professionals and learners understand timber as a material and avoid common – often costly – mistakes. The series runs as follows:

• Specifying and selecting timber – what’s the criteria? (3 September)
• Trees to commercial timber species (17 September)
• Wood material structure and properties (1 October)
• Moisture in timber (15 October)
• Understanding and how to account for moisture in wood (5 November)
• Natural durability (19 November)
• Quality of timber – perception and confusion (3 December)
• Coatings (21 January 2026)
• Modified woods (04 February 2026)
• Panel products (18 February 2026)
• Introduction to engineered products (04 March 2026)
• Strength grading (18 March 2026)
• Understanding wood degrading insects and micro-organisms (01 April 2026)