T-Shaped Valley Truss Roof
A gabled roof with a wing across the middle of one long side (a T plan), framed with plated timber trusses: Fink trusses in the main run, Fink trusses in the wing with a two-ply girder at the junction, and valley trusses stepping down on the main roof inside the wing footprint. Main length and span, wing span and length, Pitch, largest truss spacing and overhang, Truss member thickness and depths
Details
Category: Roof Framing › Timber Roof Framing › Hip and Valley Roofs
By Huu Khanh Nguyen · Updated November 4, 2026
Parameters
| Name | Default | Unit |
|---|---|---|
| Length | 9000 | mm |
| Span | 7000 | mm |
| Wing Span | 5000 | mm |
| Wing Length | 6000 | mm |
| Pitch | 30 | ° |
| Maximum Truss Spacing | 600 | mm |
| Overhang | 450 | mm |
| Member Thickness | 35 | mm |
| Chord Depth | 97 | mm |
| Web Depth | 70 | mm |
| Width | span + wingLength + overhang | mm |
| Depth | length + chordThickness | mm |
| Height | (span / 2 + overhang) * slope + heel | mm |
| Slope | Math.tan(pitch * Math.PI / 180) | |
| Heel Height | chordDepth / Math.cos(pitch * Math.PI / 180) | mm |
| Saddle Truss Minimum Span | Math.max(2 * 600 / slope, 2 * (heel + chordDepth + webDepth) / slope) | mm |
| Wing Centre | length / 2 | mm |
| Valley Truss Spaces | Math.ceil(wingSpan / 2 / maximumSpacing) | |
| Valley Truss Spacing | wingSpan / 2 / valleyBays | mm |
| First Valley Truss | Math.ceil(Math.max(saddleMinSpan, maximumSpacing) / (2 * valleyStep)) | |
| Valley Trusses | Math.max(valleyBays - firstValley, 0) |