Scissor Truss
A plated timber scissor truss: two rafters, a ceiling chord that slopes up from each heel to a flat centre section, a king post, two diagonal webs and two short posts under the rafters, drawn as members without connector plates. Span, pitch and overhang, The ceiling chord rises ten degrees less than the rafter, Member thickness and chord and web depths
Details
Category: Roof Framing › Straight Truss Roofs › Timber Trusses
By Huu Khanh Nguyen · Updated November 4, 2026
Parameters
| Name | Default | Unit |
|---|---|---|
| Span | 9000 | mm |
| Pitch | 25 | ° |
| Overhang | 450 | mm |
| Member Thickness | 35 | mm |
| Chord Depth | 97 | mm |
| Web Depth | 70 | mm |
| Slope | Math.tan((pitch * Math.PI / 180)) | |
| Heel Height | chordDepth / Math.cos((pitch * Math.PI / 180)) | mm |
| Ceiling Node Fraction | 0.3044 | |
| Ceiling Node Position | span * nodeFraction | mm |
| Ceiling Slope | Math.tan((pitch - 10) * Math.PI / 180) | |
| Ceiling Chord Vertical Depth | chordDepth / Math.cos((pitch - 10) * Math.PI / 180) | mm |
| Width | span + 2 * overhang | mm |
| Depth | chordThickness | mm |
| Height | (span / 2 + overhang) * slope + heelHeight | mm |