Trussed rafters

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Widely used for a range of building types, trussed rafters are an economical, versatile and straightforward solution to providing a roof to a building.

Trussed rafters are individually designed prefabricated structural components made from strength-graded timber members of the same thickness, joined together with punched metal plate connectors. Available as a proprietary product from various suppliers, trussed rafter components are manufactured to design code standards. They can be used to provide a structural framework to support a building’s roof fabric, room ceilings and floors.

This Wood Information Sheet focuses on how to design for and install trussed rafter products and is intended for architects, engineers and builders using trussed rafter components. It is an overview of the subject with signposts to more detailed sources that are listed at the end.



  • Introduction
  • Room in the Roof (RIR or attic) trussed rafters
  • Standards and quality control
  • Materials
  • Trussed rafter design
  • Roof design
  • Handling, storage and installation


This Wood Information Sheet was reviewed in April 2017 and minor corrections have been made.

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