Prefabricated House Joint Leakage

The treatment of joint leakage in prefabricated houses requires targeted methods based on the type of joint, with the core focus on addressing issues such as cracking in rigid connections and failure of sealing materials. The specific treatment plans are as follows:

I. Treatment of Joint Leakage in Prefabricated Panel Buildings

This type of leakage is often caused by cracking in rigid joint-filling materials (such as fine aggregate concrete and cement mortar) due to temperature changes or building settlement. Treatment involves covering the joint area with flexible waterproof materials to form a continuous waterproof barrier:

1. Material Selection: Prioritize the use of highly extensible sheet-type waterproof materials (such as SBS modified bitumen sheets). Their hot-melt application ensures firm adhesion to the substrate; for joint treatment, acrylic ester coatings can be used to enhance sealing reliability.
2. Construction Key Points:
   • Precise Leak Location: Determine the leakage location through water injection tests or infrared thermal imaging technology to avoid blind construction.
   • Substrate Preparation: Thoroughly clean the joint surface of laitance and dust, ensuring it is dry and free of oil stains; otherwise, the sheet may delaminate.
   • Overall Coverage: The sheet must cover the entire floor surface, especially above the splicing joints, to form a seamless waterproof layer.

II. Treatment of Joint Leakage Between Prefabricated Roof Panels

These joints, being constantly exposed to the outdoors, are prone to leakage due to material aging or construction defects. Treatment requires layered repair:

1. Removal of Old Materials: Remove the waterproof coating, insulation layer, and old joint-filling materials from the leaking area. For unfilled areas, chisel a 20×20mm V-shaped groove along the crack to increase the adhesion of the joint-filling material.
2. Elastic Joint Filling: Fill the V-shaped groove with polyurethane or silicone elastic materials, whose deformation resistance can accommodate minor movements of the roof panels.
3. Reinforcement Layer Construction: After applying a waterproof coating to the filled joint surface, apply a layer of fiber cloth strips and then apply the coating again to form a "one-cloth-two-coat" reinforcement layer, enhancing crack resistance.
4. Acceptance Criteria: After construction, a water spray test must be conducted for more than 2 hours without leakage to be considered qualified.

III. Treatment of Joint Leakage in Prefabricated Exterior Wall Panels

The joints in exterior wall panels are subject to stress concentration, and leakage is often caused by delamination of the sealant from the substrate or incorrect selection. Treatment requires strict control of the construction process:

1. Substrate Preparation: Use a wire brush or angle grinder to remove laitance and mold release agents from both sides of the joint. Blow off dust with compressed air, wipe with acetone, and confirm dryness.
2. Primer Application: Apply a dedicated primer, which forms a chemical bonding layer after drying, enhancing the adhesion of the sealant.
3. Sealant Selection: Prioritize the use of silicone sealants (with joint deformation capacity of ±25% to ±50%), avoiding acrylic sealants (with deformation capacity of only ±5% to ±10%).
4. Sealant Application: Use mechanical application to ensure a full sealant bead. The nozzle should penetrate to the bottom of the joint to avoid air pockets.

Treatment Key Points: All plans must ensure reliable material quality, a dry and clean construction area, and strict adherence to construction standards. After leakage treatment, regular inspections should be conducted, with a focus on checking the joint sealing status before the rainy season.