Anatomy of a roof truss

Anatomy of a Roof Truss

A Roof Truss is a structural component of houses or commercial buildings that support the weight of roof timbers and coverings.    

 “A roof truss (sometimes refered to as a joist) is a structural framework of beams (rafters, posts, struts) designed and engineered to bridge the space above a room and to provide the necessary support for a roof.”

 Roof trusses are usually designed and engineered for each project, ensuring that they offer the optimal support for your roof.

Not everyone understands roof truss manufacturer’s terminology, which is why we have compiled this useful illustration with a list of roof truss components and a brief definition of each component:

 

Anatomy of a roof Truss

APEX (Peak): The highest point on a joist where the sloping top chords meet.

BATTEN: Roofing battens or ceiling battens. Usually, timber members fixed at right angles to the joist chords to support roof tiles or ceiling material. Also provides lateral restraint to the truss.

BOTTOM CHORD (BC) or TIE BEAM: the Horizontal or sloping member that establishes the lower edge of a truss and usually carries combined bending and tension stresses.

BRANDERING: Timber member fixed to the bottom of the joist to support the ceiling.

CLEAR SPAN: The horizontal distance between interior edges of supports.

HEEL: The point on a joist at which the top chord and bottom chord intersect.

JOINT (NODE): Point of the intersection of one or more web(s) with a chord.

NAIL PLATE: A galvanized steel plate punched to form a nail pattern integral with the plate and used to connect timber members.

NODE-POINT/JOINT: A point of intersection of two or more members that make up the panels of a joist.

NOMINAL SPAN: The horizontal distance between the outside edges of the supports (wall plates) – usually the tie beam length.

OVERHANG: The extension of the top chord of a truss beyond the bearing support.

PLUMB CUT: A vertical cut to the end of the top chord to provide for vertical (plumb) installation of the fascia or gutter

SPLICE JOINT: The point at which two chord members are joined together to form a single member

TOP CHORD (RAFTER): Truss member forming top edge of a truss.

WALL PLATE (BEARING): Structural support of trusses (usually walls), normally with a timber wall plate.

WEB: The internal members of a truss. Usually, only subject to axial loads due to truss action.

Contact the specialist in Roof Truss Manufacturing for your roofing project!

TechniStrut (Pty) Ltd offers a complete roofing supply solution. While our core business is the manufacture of Timber Roof Trusses, we also supply Roof Sheeting, Roof Tiles, and all other roofing materials required to install a complete roof.

We supply roof trusses to Johannesburg, Pretoria and the greater Gauteng province. 

Speak to one of our experienced consultants about your roofing requirements.

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