Gable Roof Prefabricated House Structure

In the gable roof prefabricated house structure, the gable wall is a key load-bearing component of the roof, and its structural form and applicable conditions need to be comprehensively determined based on the building type, seismic requirements, and load distribution.

Basic Principles of Gable Wall Load-Bearing

Gable wall load-bearing is a common structural form for pitched roofs. By constructing the transverse wall (i.e., the gable wall) of the house into a triangular structure, purlins or rafters are directly placed on the gable wall to bear the roof load. This structure utilizes the principle of triangular stability to transfer the vertical and horizontal loads of the roof to the gable wall, which then transfers them to the foundation. For example, the common 'hard gable with purlins' construction in rural self-built houses achieves roof support by directly placing purlins on rigid gable walls, mainly applied in masonry and steel structure buildings.

Applicable Conditions and Limitations

1. Seismic Performance Limitations: The hard gable with purlins structure offers flexible layout but has significant seismic performance deficiencies. Wooden houses are not suitable for this structure due to insufficient material ductility; it is explicitly prohibited for use in high-rise building roofs and areas with seismic fortification intensity above 8 degrees, as earthquake action may lead to gable wall instability. If it must be used, seismic structural measures such as closed ring beams and wall ties should be implemented to enhance overall integrity, and triangular support structures should be constructed at the top of the gable wall, with steel nails used to fix the purlins to improve lateral resistance.
2. Load Distribution Requirements: In industrial buildings such as workshops, the construction of gable roofs needs to be adjusted according to the span. If the roof width is small (e.g., less than 6 meters) and the rafters span the floor beams, a connecting beam may not be poured, and the load can be directly borne by the gable wall; if the span is large, a connecting beam should be poured to evenly distribute the roof load to each masonry unit, preventing wall expansion due to uneven settlement or horizontal force action.

Construction Key Points

1. Material Selection: High-strength masonry materials (such as concrete blocks or fired bricks) should be used for the gable wall, and the mortar strength should meet design requirements to bear the roof load.
2. Structural Measures: A reinforced concrete ring beam should be set at the junction of the gable wall and the roof to enhance wall integrity; purlins should be reliably connected to the gable wall using wall ties to prevent slippage; for large-span structures, structural columns should be added inside the gable wall to improve collapse resistance.
3. Detail Handling: The top of the gable wall should be constructed into a triangular support structure and fixed with steel nails to avoid local stress concentration; wooden purlins should undergo anti-corrosion treatment to extend their service life.