Room In Roof Truss
A plated timber room-in-roof (attic) truss: two deep rafters, a floor chord, two posts that frame the room and a collar under the apex, drawn as members without connector plates. Span, pitch and overhang, 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 | 8000 | mm |
| Pitch | 40 | ° |
| Overhang | 450 | mm |
| Member Thickness | 47 | mm |
| Chord Depth | 197 | mm |
| Web Depth | 145 | mm |
| Slope | Math.tan((pitch * Math.PI / 180)) | |
| Heel Height | chordDepth / Math.cos((pitch * Math.PI / 180)) | mm |
| Post Position | span * 0.2114 | mm |
| Width | span + 2 * overhang | mm |
| Depth | chordThickness | mm |
| Height | (span / 2 + overhang) * slope + heelHeight | mm |