Timber I-joists: applications and design

TRADA image

Timber I-joists are engineered structural components that are widely used in the UK, particularly as floor joists. Its high strength-to-weight ratio and economy in use of materials make them popular when designing for long-spans and multi-storey structures. I-joists shrink or swell less than solid wood when the ambient conditions change.

I-joists are factory produced in the UK and elsewhere, with extensive quality control checking to ensure constancy of performance. The route to market is via third-party certification that establishes safe design values for use with design codes.

This Wood Information Sheet (WIS) covers the many considerations to be made when working with I-joists, including the potential need for metal strapping or the need for temporary bracing or sheathing during construction due to the tendency for unrestrained joists to twist due to buckling when compressed.

 

Contents:

  • Product certification
  • Structural principles
  • Application of I-joists
  • Details for design and construction
  • Engineering design

Suggested Reading

Contemporary non-metallic timber connectionsnavigation-arrow

In buildings such as swimming pools, grit salt storage facilities and agricultural spaces there is a need for the provision of corrosion-resistant structure. Timber structures are an effective solution in these instances. However, within these structures it is also necessary to use corrosion-resistant connections.

In recent years, interest in...

01/01/2012 |  Research Summarie  

Strutting in timber floorsnavigation-arrow

Strutting plays a useful role in promoting composite structural behaviour of the components that form a timber floor.

The effects of strutting are to:

  • reduce local deflections by transferring load to adjacent joists (load sharing)
  • improve joist stability by providing lateral support to joist edges
  • reduce the...

04/05/2018 |  Wood Information Sheet  

Glulam - connecting with future developmentsnavigation-arrow

Glued laminated timber (glulam) beams and columns have been used for decades as an engineered timber product that allows designers to span further, carrying heavier loads while retaining all of the benefits of using wood in structures.

Article from Timber 2016 Industry Yearbook

01/01/2016 |  Magazine Article