Self-Built House Roof with Prefabricated Tiles

When using prefabricated tiles for the roof of a self-built house, it is essential to consider the structural form, construction points, and potential issues comprehensively to ensure structural safety and functional requirements.

1. Common Structural Forms

1. Bitumen Felt + Wooden Wedge Fixing Method
   After laying a leveling layer on prefabricated reinforced concrete hollow slabs or cast-in-place slabs, cover with bitumen felt as a waterproof layer. Fix the felt pressing strips and tile hanging strips using wooden wedges, and finally lay the tiles. This method relies on the waterproof performance of the bitumen felt, but the connection between the wooden wedges and the prefabricated slabs is prone to loosening due to thermal expansion and contraction or vibration, leading to waterproof layer failure.
2. Waterproof Cement Mortar Tile Adhesion Method
   Directly apply waterproof cement mortar on the roof slab surface and adhere the tiles to it, commonly used in antique-style buildings. This method is simple in construction but requires high standards for the mix ratio and construction process of the cement mortar. It is necessary to ensure the bonding strength between the mortar, the prefabricated slab, and the tiles to avoid hollowing or detachment.

2. Core Issues and Risks

1. Joint Cracking
   Prefabricated slabs are installed in sections, and cracks can easily form at the joints between slabs due to settlement, temperature changes, or construction errors, becoming channels for rainwater leakage. If the waterproof layer is not properly treated, cracks will accelerate expansion, affecting the durability of the roof.
2. Difficult Waterproofing
   Traditional waterproof materials (such as bitumen felt) have limited adhesion to prefabricated slabs. Additionally, after tile laying, there are numerous拼接 (should be 'joint' in English, here kept as is for context of translation challenge) seams on the roof, which need to be sealed using tile hanging strips, felt pressing strips, and other structures. However, improper detailing can still lead to leakage.
3. Poor Thermal Insulation
   Prefabricated slabs are usually thin and mostly have a hollow structure inside, resulting in low thermal resistance. In winter, this can easily lead to heat loss from the interior, while in summer, heat absorption by the roof may increase the air conditioning load.
4. Low Seismic Resistance
   Prefabricated slabs are assembled as a whole, with weak stiffness in the connections between slabs. Under seismic action, they are prone to dislocation or detachment, especially in earthquake-prone areas. It is necessary to enhance safety by adding seismic structural measures (such as adding tie bars) according to the "Code for Seismic Design of Buildings."

3. Key Construction Points

1. Waterproof Layer Reinforcement
   Preferably use polymer waterproof membranes or polyurethane waterproof coatings instead of traditional bitumen felt to improve adhesion and durability with prefabricated slabs. Sealant should be used to fill joints, and non-woven fabric should be applied for reinforcement.
2. Thermal Insulation Layer Installation
   Add high-efficiency thermal insulation materials such as extruded polystyrene boards (XPS) or rock wool boards above the waterproof layer. The thickness should be determined according to local climate conditions (usually ≥50mm) to reduce thermal bridge effects.
3. Standardized Design Verification
   Before construction, verify whether the bearing capacity, span, and reinforcement of the prefabricated slabs comply with design specifications to avoid structural deformation due to overloading. In earthquake zones, add seismic structural measures according to the "Code for Seismic Design of Buildings."