How to Construct Eaves for Prefabricated Panel Houses

The construction of eaves for prefabricated panel houses requires a combination of prefabricated concrete cantilever eave techniques and common rural practices, following the steps and key points outlined below:

I. Construction Preparation and Foundation Positioning

1. Technical Preparation: Familiarize with the construction drawings, prepare a specialized plan, conduct technical briefings for workers, and clarify the dimensions of the cantilever eaves, steel bar configurations, and drainage requirements.
2. Line Setting and Positioning: Snap lines on the wall to indicate the installation positions of the prefabricated panels and the elevation of the beam bottom, ensuring installation accuracy. Determine the overhang range of the cantilever eaves based on the design width (recommended 60-80 cm, which can be widened to 1.2 meters for higher floors or areas with heavy rainfall). If the overhang exceeds 1.2 meters, additional cantilever beams or supports must be installed.

II. Lifting and Formwork Installation

1. Lifting Safety: Check the reliability of lifting hooks, ropes, and rings. Lift the prefabricated panels following the principle of 'low before high, near before far' to avoid collisions with the wall.
2. Formwork Requirements:
   • Install wooden wedges at the wall installation positions as formwork support points, ensuring tight formwork joints without mortar leakage gaps and a smooth, flat surface.
   • The formwork support system must be independently erected to avoid direct force on the cantilever eave structure.

III. Cantilever Eave Design and Drainage Optimization

1. Shape Design:
   • Adopt a 'triple-layer' design (multi-layer moldings or corbels forming a stepped profile) to enhance drainage efficiency and improve aesthetics.
   • Combine with gutters to form an organized drainage system. The recommended gutter width is 30-60 cm, maintaining a 2% drainage slope.
2. Drainage and Apron Slope: The apron slope width should be more than 20 cm wider than the overhang length of the cantilever eaves, with a slope of 5% to prevent rainwater from eroding the foundation.

IV. Steel Bar Configuration and Concrete Construction

1. Steel Bar Anchoring: The main steel bars should be anchored into the main structure for a length of at least 30 times the diameter of the steel bars. Radiating distribution bars should be added at the root to prevent cracks.
2. Concrete Pouring:
   • Use concrete of the same strength grade as the main structure and vibrate it in layers to ensure compactness.
   • The formwork should not be removed until the concrete strength reaches 100% to avoid structural damage.

V. Material Selection and Detail Handling

1. Material Adaptation: Select materials according to needs, such as wood (traditional style), metal (modern simplicity), tiles (antique effect), or composite materials (lightweight and durable), balancing aesthetics and durability.
2. Edge Treatment: Design drip lines or eagle-beak shapes at the edges of the cantilever eaves to prevent rainwater from flowing backward. Seal the joints with waterproof mortar or sealant.

Key Tips: When the overhang width of the cantilever eaves exceeds 1.2 meters, the load-bearing capacity must be reviewed by a structural engineer, and additional support components must be installed. During rainy season construction, strengthen drainage measures to avoid the impact of water accumulation on concrete quality.