Prefabricated House Roof Waterproofing

Prefabricated house roof waterproofing requires systematic treatment tailored to the characteristics of the spliced structure, with the core focus on addressing issues such as board joint leakage, base layer defects, material compatibility, and weak points in the gutter. The specific construction plan and precautions are as follows:

I. Standardized Construction Plan

1. Base Layer Treatment
   Thoroughly remove the original ineffective waterproof layer and repair defects such as unevenness, cracks, and sanding on the base layer to ensure a flat and solid surface. The quality of the base layer directly affects the adhesion of the waterproof layer. If there are hidden defects (such as hollow areas or looseness), they must be thoroughly repaired through cutting and filling to prevent hidden leakage caused by water flowing beneath the waterproof layer.

2. Board Joint Reinforcement
   Use rigid filling materials (such as polymer cement mortar) to fill the gaps between prefabricated panels, enhancing the overall structural integrity. Board joints are the primary pathways for water infiltration. Ordinary materials are prone to cracking due to dynamic displacement of the panels. Therefore, it is essential to select filling materials that are resistant to stretching and aging and ensure proper compaction through mechanical means to reduce the risk of cracking in the later stages.

3. Comprehensive Waterproofing
   Lay thickened national standard waterproof membranes (such as high-polymer modified bitumen membranes) to form a continuous waterproof layer. The membranes must undergo on-site inspection for performance indicators such as tensile strength and heat resistance to ensure compliance with the requirements of the 'General Code for Waterproofing of Buildings and Municipal Engineering'. For flat roofs, Class I waterproofing should have no less than 3 layers of protection, while Class II should have no less than 2 layers, with at least one layer being a waterproof membrane. Multiple layers of protection are used to resist leakage.

4. Node Reinforcement
   Adopt specialized exposed waterproofing techniques for areas prone to leakage, such as gutters and roof penetrations. For example, gutters should be coated with weather-resistant waterproof coatings and additional layers should be added; the roots of pipes should be sealed with sealant and reinforced with membrane strips. Conventional materials are prone to aging and detachment due to water accumulation, so it is necessary to select exposed materials that are resistant to ultraviolet rays and corrosion.

5. Warranty and Maintenance
   After construction is completed, a written warranty of more than 5 years should be provided, along with regular inspections and maintenance. If leakage occurs during the warranty period, the construction unit should provide free repairs to ensure long-term waterproofing effectiveness.

II. Key Precautions

• Environmental Limitations: Construction should avoid rainy days, snowy days, and winds exceeding Force 5 on the Beaufort scale. The temperature should be suitable for the material and process requirements (e.g., the construction temperature for bitumen membranes should not be lower than 5°C).
• Systematic Treatment: Avoid only performing local repairs or surface coating. It is necessary to provide comprehensive protection from the base layer to the surface layer to address structural leakage weaknesses.
• Material Selection: Prioritize the use of qualified materials that have passed on-site inspection, such as national standard genuine waterproofing materials from Oriental Yuhong, to ensure that performance indicators such as resistance to stretching and aging meet the standards.