Repair of Leaks in Prefabricated Panel Houses

Leaks in prefabricated panel houses require a systematic renovation approach for repair, as traditional local patching cannot address the root cause of the problem.

I. Core Causes of Leaks in Prefabricated Panel Houses

The roof of a prefabricated panel house is composed of multiple independent concrete panels joined together, with panel joints being the primary channels for water infiltration. Over time, due to temperature variations and foundation settlement, these joints are prone to cracking and displacement, causing the ordinary waterproof layer to crack and delaminate. Additionally, hidden defects such as unevenness, sanding, and peeling in the base layer make it difficult for local repairs to block the path of water seepage, leading to recurrent leaks.

II. Steps for Systematic Repair Plan

1. Base Layer Treatment

   • Thoroughly remove the original loose leveling layer and aged waterproof layer on the roof to prevent residues from affecting the adhesion of the new waterproof layer.
   • Repair cracks, holes, and sanding areas in the base layer to ensure a flat and solid surface, eliminating hidden risks of water seepage.

2. Panel Joint Reinforcement

   • Use rigid filling materials (such as polymer cement mortar) to deeply fill the panel joints, enhancing their resistance to dynamic deformation.
   • After filling, compact and smooth the surface to prevent re-cracking due to material shrinkage or temperature changes.

3. Full-Area Waterproofing

   • Employ national standard thickened waterproof membranes (such as SBS modified bitumen membranes) for overall laying, covering the entire roof area.
   • The overlap width of the membranes must comply with regulations (≥10cm), and hot-melt or cold-adhesive processes should be used to ensure sealing and prevent the spread of local leaks.

4. Gutter Reinforcement Treatment

   • For areas prone to water accumulation, such as gutters and eaves, use specialized exposed-type waterproof coatings (such as polyurethane waterproof coatings) for enhanced treatment.
   • The coating should be applied in multiple layers with a thickness of ≥2mm and extended at least 20cm beyond the surrounding area to improve weather resistance and UV resistance.

III. Advantages of the Plan and Case Verification

Traditional local joint patching or surface coating can only temporarily alleviate leaks and cannot solve the problem of recurrent cracking caused by structural deformation. The systematic renovation plan forms multiple waterproof barriers through the coordinated steps of base layer repair, panel joint reinforcement, full-area waterproofing, and key area enhancement. For example, the Phase I project of Zhonghuan Jiayuan in Putuo District, Shanghai, adopted this plan for construction, using genuine national standard materials from Oriental Yuhong. After completion and acceptance, a 5-year warranty was provided, completely resolving the long-standing leak problem.

Tip: Choose a professional team for construction to ensure materials meet national standards and avoid secondary leaks caused by material or process defects.