Metal web joists

Engineered wood products and an introduction to timber structural systems, published by the Structural Timber Association, defines metal web joists as “shallow parallel chord trusses manufactured using similar techniques to that used for trussed rafters comprising a member with flanges (or chords) usually made from softwood and with metal or timber strutting to form the webs'.

Metal web joists are also referred to as open web joists.

The Code of Practice for Engineered Wood Products, published by the Engineered Wood Products Committee of the UK Timber Frame Association, states that ‘open web joists are structural members manufactured with chords made from softwood or laminated veneer lumber (LVL) and with metal or timber strutting to form the webs. The chords are connected to each other by a system of triangulation, which may be provided by thin gauge steel webs incorporating integral nail-plated zones’.

Metal web joists are primarily used for floor and roof joists. They are generally preferred over thin webbed joists (or I-joists) for these applications, because this type of joist tends to provide space for services as well as a structural zone.

[edit] Related articles on Designing Buildings

• Joist.
• Rolled steel joist (RSJ).
• Thin webbed joists.
• Timber post and beam construction.
• Timber engineered structural frames.
• Types of beam.
• Types of flooring.

[edit] External resources

• Engineered Wood Products Committee, UK Timber Frame Association, The Code of Practice for Engineered Wood Products.
• Structural Timber Association, Engineered wood products and an introduction to timber structural systems.