Types of Timber Roof Trusses

Timber roof trusses are a popular choice for their aesthetic appeal and structural reliability in building construction. 

Here are some common types of timber roof trusses:

King Post Truss: This is one of the simplest and oldest truss types, typically used for shorter spans. It features a central vertical post (king post) supporting the truss apex, making it efficient for spans up to about 8 meters.

Queen Post Truss: Similar to the king post truss, the queen post truss uses two vertical posts (queen posts) instead of one. This design allows for longer spans, typically up to around 12 meters, and provides a more open space in the attic area.

Fink Truss: A common choice for residential buildings, the Fink truss is characterized by its "W" shaped web configuration. It's designed for medium to long span roofs, typically between 10 and 20 meters, providing good support for heavy loads and allowing for some attic space.

Howe Truss: In this configuration, the vertical members and diagonals face opposite directions, which is excellent for larger spans requiring sturdy support. It is similar to the Pratt truss but uses wood instead of metal for construction.

Pratt Truss: This truss uses diagonal members sloping towards the center of the span, counteracted by vertical members in the middle. It is effective for longer spans and can be adapted for use with timber, although it’s more commonly seen with steel.

Scissor Truss: Offering a vaulted ceiling, the scissor truss has sloping upper chords that cross each other, connecting to the opposite joint at the base, forming a shape resembling a pair of scissors. This truss is ideal for creating an open and airy feel in a room.

Gambrel Truss: Resembling the shape of a barn roof, this truss allows for a more usable loft space, thanks to its two different slopes on each side of the apex. The steep lower slope provides more headroom.

Mansard Truss: Similar to the Gambrel, the Mansard truss features two slopes on each side, with the lower slope being much steeper. This design maximizes interior room under the roof, allowing for additional living space, typically used in commercial building designs.

Each type of truss offers unique advantages and is suited to different structural requirements and aesthetic preferences.