Roof-Terminology6

BATTEN CENTRES: The distance, measured along the slope of the top chord, between battens.

BEARING WIDTH: The horizontal width of the structural support of trusses – usually the timber wall plate.

BOTTOM CHORD PITCH: The angle of the bottom chord (BC) or tie beam with respect to the horizontal (see Figure 7).

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

EFFECTIVE LENGTHS: The distance, measured along the slope of the top chord, between lateral bracing members – usually purlins – connected to the top chord.

HEEL HEIGHT: The vertical height from the bottom of the bottom chord to the top of the top chord at the heel line (usually at the outside edge of the bearing).

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

OVERALL HEIGHT: The vertical height from the bottom of the bottom chord to the top of the apex.

OVERHANG LENGTH: The horizontal length of the extension of the top chord beyond the bearing support.

PANEL LENGTH: The distance between the centres of adjacent joints or nodes, measured horizontally along the chords (see Figures 6 and 7).

PITCH or SLOPE: The angle of a chord with respect to the horizontal.

PURLIN CENTRES: The distance, measured along the slope of the top chord, between purlins.

STUB HEIGHT: The vertical height from the bottom of the bottom chord to the top of the top chord at the outside edge of the support (wall plate).

TOP CHORD PITCH: The angle of the top chord (TC) or rafter with respect to the horizontal.

Roof-Terminology7

 

 

Roof Trusses Loading & Engineering | Roof Trusses Sundry Timbers Connected To Trusses