Chengdu Prefabricated Slab House Renovation

When renovating prefabricated slab houses in Chengdu, it is essential to focus on waterproofing, structural protection, and the selection of construction methods. Specific recommendations are as follows:

I. Waterproofing is Key

The Chengdu Basin has high humidity, and the seams in prefabricated slab floors can easily become channels for water seepage. If waterproofing is inadequate, moisture can penetrate through the seams, leading to mold and peeling on walls. Key measures include:

1. Double-coat waterproofing process: Both walls and floors should be coated with waterproofing paint twice to ensure full coverage without blind spots. The waterproofing height in shower areas should be extended to at least 1.8 meters to prevent moisture from seeping in from the top.
2. Edge detail treatment: The surface of the waterproofing layer should be smooth and free of sand holes. Edges, such as corners and pipe roots, should be straightened and reinforced with additional coating to prevent leakage due to construction flaws.
3. Secondary drainage system: If bathroom renovation is involved, a secondary drainage outlet must be installed to prevent accumulated water in the backfill layer from seeping through the slab seams to the floor below or causing dampness and odor.
4. Hole repair: If holes in the prefabricated slabs are exposed during demolition or drilling, they should be promptly repaired with waterproof mortar or specialized sealing materials to prevent future leaks.

II. Structural Protection Requires Caution

The load-bearing capacity of prefabricated slab floors is limited, and demolition or drilling may compromise structural stability. Precautions include:

1. Avoid large-scale demolition: Do not demolish prefabricated slab floors unless absolutely necessary. If layout adjustments are needed, prioritize using lightweight partitions or furniture to divide the space.
2. Drilling restrictions: If drilling into the floor is necessary (e.g., for installing lighting fixtures or pipes), confirm in advance that the hole locations avoid main reinforcement bars and control the hole diameter (generally not exceeding 50mm). Repair the holes immediately after drilling.
3. Load-bearing wall protection: It is strictly prohibited to demolish or modify load-bearing walls or shear walls. If partial renovation is involved, a professional structural engineer must assess the safety.

III. Construction Methods Should Match Needs

1. Commercial space renovation: Prefabricated decoration can be prioritized, reducing the construction period by approximately 30% and lowering dust and noise by more than 60%, making it suitable for scenarios where operations continue during construction.
2. Residential renovation: If the original building height is less than 2.8 meters, prefabricated raised floors combined with suspended ceilings may compress the space and should be chosen with caution. If load-bearing wall demolition or extensive waterproofing is involved, traditional wet construction methods should still be used to ensure construction quality.

IV. Recommendations for Renovation Companies

1. Chengdu Lilin Design Studio: Adopts a 'renovate first, pay later' model and specializes in addressing dampness issues in old houses. It offers double-layer waterproofing and other processes, suitable for homeowners with high waterproofing requirements.
2. Chengdu 80s Renovation Team: Focuses on construction and uses standard processes such as double-layer waterproofing and wall mesh reinforcement to prevent cracking. It is suitable for homeowners who already have design drawings and need efficient implementation.