11/01/2026
a technical illustration detailing various timber roof truss systems and their corresponding structural joints. It functions as a visual guide for carpentry and traditional timber framing, showing how different spans (distances between supports) require different internal bracing configurations.
1. ROOF TRUSS CONFIGURATIONS (LEFT SIDE)
The diagrams labeled with Greek letters ( through ) show the overall profile of different truss types.
• Small Spans (4–6 m): Shown in diagram , these use a simple triangular frame with basic diagonal braces.
• Medium Spans (6–9 m): Diagram illustrates a more complex truss with multiple internal struts and a central "king post" or collar tie to prevent sagging over a longer distance.
• Attic/Mansard Frames: Diagrams and show steeper pitches and vertical supports, which are typically used to create usable living space (an attic) within the roof structure.
• Measurements: The horizontal arrows indicate the recommended span in meters (e.g., "3–5 м" or "6–9 м").
2. STRUCTURAL JOINERY DETAILS (RIGHT SIDE)
The numbered circles on the left diagrams correspond to the detailed 3D exploded views on the right. These illustrate how the wooden beams are cut, notched, and fastened together.
• Heel Joints (1, 5, 10, 13): These show how the rafters (the sloped beams) connect to the wall plates or tie beams. They often feature notches (birds-mouth cuts) and metal plates or spikes to resist the outward "thrust" of the roof.
• Peak/Apex Joints (3, 7, 11): These detail the "ridge" connections where the rafters meet at the highest point. Some show simple miters, while others show more complex interlocking joints.
• Bracing & Struts (2, 4, 6, 8, 12): These depict how internal diagonal braces are notched into the main rafters and vertical posts to provide rigidity.
• Splice Joints (9, 19): These show how two shorter pieces of timber are joined end-to-end (scarf joints) to create a single long beam, often reinforced with wooden dowels or metal bolts.
3. KEY COMPONENTS VISUALIZED
• Wood Grain: The illustration emphasizes the direction of the wood grain, which is critical for structural integrity.
• Fasteners: You can see small grey lines representing nails, spikes, or bolts used to secure the connections.
• Bearing Blocks: The blue-grey blocks at the bottom of several joints (like 10 and 13) represent the masonry wall or the "sill plate" upon which the entire roof sits.
• Note: This appears to be a pedagogical diagram, likely from a Russian engineering or carpentry manual (indicated by the "м" for meters and Cyrillic lettering).
