Waterproofing for Roofs of Prefabricated Structure Houses

Waterproofing for roofs of prefabricated structure houses requires systematic treatment to achieve long-lasting waterproofing, addressing characteristics such as numerous拼接缝隙 (joint gaps) and frequent deformation. The core points are as follows:

I. Analysis of the Core Causes of Leakage

The roof of a prefabricated panel house is composed of multiple independent concrete panels joined together, with panel joints being natural channels for water infiltration. Over time, affected by temperature differentials, settlement, and loads, these panel joints are prone to cracking and displacement. If the base layer has issues such as unevenness, sanding, or peeling, it can lead to water flowing beneath the waterproof layer, resulting in hidden leakage. For example, the first phase of the Shanghai Zhonghuan Jiayuan project experienced repeated leakage due to panel joint cracking, which was ultimately resolved through a systematic solution.

II. Key Steps in Waterproofing Construction

1. Base Layer Treatment
   It is necessary to remove obstacles across the entire area and meticulously repair defects such as honeycomb cracks and loose, sandy areas to ensure the base layer is flat and solid. If the base layer is uneven, it should be leveled with cement mortar to prevent the waterproof layer from cracking due to base layer defects.

2. Panel Joint Reinforcement
   Rigid filling materials (such as polymer cement mortar) should be used to reinforce panel joints and block water pathways. If structural limitations prevent grooving, priority should be given to filling gaps with filling materials and complementing with a full-area membrane waterproofing system to avoid relying solely on local repairs, which can lead to tearing of the waterproof layer.

3. Full-Area Waterproofing
   Use national standard thickened membranes (such as high-polymer modified bitumen membranes) for full-area laying to form a continuous waterproof layer. For flat roofs, Class I waterproofing requires no less than 3 layers, and Class II waterproofing requires no less than 2 layers, with at least one layer being a membrane waterproof layer to avoid the problem of local repairs being a "temporary fix".

4. Gutter Reinforcement
   For areas prone to water accumulation, such as gutters, use weather-resistant waterproof coatings or membranes with specialized exposed treatment processes to prevent aging and detachment. For example, the Shanghai Zhonghuan Jiayuan project effectively resolved leakage caused by water accumulation through gutter reinforcement processes.

III. Material and Process Standards

• Material Selection: Prioritize materials with strong tensile and deformation resistance (such as Oriental Yuhong national standard genuine waterproofing main materials) to adapt to the dynamic deformation characteristics of prefabricated panels.
• Standard Compliance: Construction should be carried out in accordance with the requirements of the "General Code for Waterproofing of Buildings and Municipal Engineering" to ensure parameters such as waterproof layer thickness and lap width meet standards.

IV. Construction Environment Requirements

Construction is strictly prohibited in rainy, snowy, or windy conditions above Force 5. The ambient temperature must be suitable for the materials and processes used (for example, the construction temperature for bitumen membranes should be above 5°C) to avoid factors such as the environment causing poor adhesion or cracking of the waterproof layer.

Case Reference: The first phase of the Shanghai Putuo District Zhonghuan Jiayuan project根治 (completely resolved) the problem of repeated leakage in the roof of prefabricated panel houses through a solution combining "base layer repair + panel joint reinforcement + full-area membrane waterproofing + gutter reinforcement" and standardized construction, providing a 5-year warranty.