Structural Beams, Porches & Timber Truss Wall Systems

Bending Beams: Design Principles & Applications

Bending beams are primarily used in structures where managing mass distribution and resisting bending forces is crucial. Within a beam subjected to bending, a pair of internal compression and tension forces develops. To improve performance, a higher torque arm (i.e., the height (canto) or width of the beam in the plane of bending) is essential. Therefore, enhancing performance isn't always about increasing the overall cross-section of the piece, but specifically its height (canto), which guarantees an optimal moment of inertia and adequate capacity to resist shear forces. However, this focus on height can sometimes be inconvenient if the prevailing interest is in the functionality of spaces, leading to the use of flat beams. Beams are constructed with various support solutions, which means their support conditions can vary considerably and, consequently, influence the design of these structural parts.

Structural Porches: Beam & Column Assemblies

A porch is an association of beams and columns, with connections of varying rigidity, forming a structural unit. Typically, the beams support the slabs and transmit loads to the pillars. These pillars, in turn, act as bending-resistant structural elements. In multi-storey buildings and bays, multiple porches often cross the structural plans, forming complex frameworks.

Wood Framing Truss Walls: Construction & Benefits

Truss walls are wood framing assemblies capable of replacing traditional masonry walls in a building. A truss wall consists of vertical pieces attached to horizontal ones. The entire assembly is triangulated by oblique pieces, known as braces, to prevent distortion and ensure structural stability.

Traditional Spanish Truss Systems & Components

In traditional construction, the spaces within the wooden framework of truss walls are filled with various materials, depending on historical variants or geographical areas. These infill materials can include cob, adobe, brick, masonry, or stone masonry, sometimes even with poorer quality materials if an exterior plaster layer ensures the protection of the truss system's filling. The traditional Spanish architectural truss system typically includes the following components:

• A sill (solera) that rests on the base or a masonry foundation.
• Posts or uprights (pies derechos) supported by the sill.
• A race or top plate (carrera) to which the posts are assembled at the top, either directly or through a shoe (zapata).
• Braces (tornapuntas), which are oblique parts that consolidate the assembly, often assembled with virotillos (short vertical pieces or noggings).
• Horns (zancas or codales), which are more resistant poles placed at angles, potentially spanning one or more stories and typically thicker than 25 cm.
• Jambs (montantes) for door and window openings. These are joined above and below the opening by lintels (dinteles) and sills (antepechos or alféizares) respectively. This construction leads to shorter spans between the pedestal posts and the race, or may involve a Pilarejo (small pillar) resting on the solera (sill plate).

Floor Integration in Timber Truss Structures

When the structure needs to support a floor or a forged (floor structure, forjado), the joists (viguetas) are placed between the race (top plate, carrera) and an overtravel piece (or ledger board, sobrecarrera). This overtravel piece supports the floor structure. The superior floor's distribution system often relies on these races, which are covered by the pavement and, where possible, are placed perpendicular to the joists for optimal load transfer.