06/05/2026
Common Timber Roof Truss Types
This technical illustration displays a curated selection of timber roof truss designs, showcasing how different internal bracing configurations—known as webs—affect the structural span and architectural utility of a building. Each model demonstrates a specific solution for distributing weight and creating unique interior spaces, ranging from standard residential spans to large-scale industrial requirements.
Key Features and Analysis
Howe Truss: Features vertical members and diagonals that face outward from the center. It is designed for medium to long spans (up to 30m) by handling compression in the vertical members.
Gambrel Truss: Characterized by its distinct "barn-style" double-slope roofline. This design is primarily used to maximize headroom and usable attic space.
Double Fan: Utilizes a fanning arrangement of diagonal members from both the top and bottom chords, providing stability for spans between 15m and 25m.
Sloping Flat: A modified flat truss designed to provide a specific drainage slope. It is a compact solution for shorter spans of 4m to 10m.
Double Fink: An evolution of the standard "W" truss. By extending the webbing pattern, it achieves significantly longer spans of up to 30m.
Inverted: Essentially an upside-down monopitch truss. This is often selected for aesthetic purposes to create a "vaulted" or unique ceiling geometry inside a structure.
Design Summary
The image serves as a practical guide for understanding the relationship between truss geometry and structural performance. By varying the orientation and frequency of the diagonal and vertical members, engineers can tailor a roof's load-bearing capacity to its intended span. These timber systems remain a staple in modern construction due to their efficiency, ease of installation, and ability to bridge large distances without the need for internal load-bearing walls.
