How to Handle Prefabricated Panel Joints in Houses

The treatment of prefabricated panel joints in houses should be selected based on the joint width, usage scenario, and renovation stage, as detailed below:

I. General Panel Joint Treatment

For ordinary panel joints with a small width (≤20mm), they can be directly filled with fine aggregate concrete. Fine aggregate concrete, composed of cement, sand, and gravel mixed in proportion, offers superior strength and durability compared to ordinary cement mortar, effectively filling gaps and preventing cracking. For wider joints (>20mm), structural reinforcement bars should be added or a cast-in-place strip should be set while filling with fine aggregate concrete. Structural reinforcement bars enhance the tensile strength of the panel joints, while the cast-in-place strip forms a continuous structure through integral concrete pouring, reducing the risk of cracking caused by stress concentration.

II. Treatment in Waterproof Areas

In areas such as bathrooms and kitchens that are frequently exposed to water, special attention should be paid to the waterproofing performance of panel joint treatment. In addition to filling with fine aggregate concrete, waterproof mortar should be applied to the surface or waterproofing membranes should be laid. Waterproof mortar, formed by mixing a waterproofing agent with cement mortar, creates a dense waterproof layer to prevent water penetration; waterproofing membranes cover the panel joints through hot melting or adhesion, further enhancing the waterproofing effect. After treatment, a closed water test is recommended to ensure no leakage occurs.

III. Crack Treatment During Renovation

If significant cracks have appeared in the house, debris inside the cracks should be cleared first to ensure tight bonding between the filling material and the substrate. For narrow cracks, cement mortar or epoxy resin adhesive can be directly filled; for wider cracks or those posing structural safety risks, the following steps should be taken:

1. Substrate Preparation: Use a small trowel to remove dust and loose particles from the cracks, rinse with water, and allow to dry.
2. Reinforcement: Adhere Dacron cloth, mesh cloth, or carbon fiber cloth to the crack surface. Carbon fiber cloth, with its high strength and corrosion resistance, effectively constrains crack expansion and enhances structural integrity.
3. Filling and Repair: Fill the cracks with cement mortar or specialized repair materials, smooth the surface, and cure until the strength meets the standard.

IV. Refined Treatment of Prefabricated Panel Splice Joints

Prefabricated panel splice joints are structural weak points and should be treated strictly following the process below:

1. Crack Cleaning: Use a small trowel to remove渣土 (debris) and floating dust from the cracks, and rinse with water until no impurities remain.
2. Joint Treatment: If the joint width is ≤5mm, fill directly with cement mortar; if the width is >5mm, first chisel into a V-shaped groove to increase the contact area between the filling material and the substrate, enhancing adhesion.
3. Reinforcement with Steel Bars: Insert 12mm thick deformed steel bars into the V-shaped groove, with the bar spacing determined according to design requirements, typically not exceeding 300mm. The steel bars should be reliably connected to the prefabricated panels to form an integral load-bearing system.
4. Concrete Pouring: Pour fine aggregate concrete and vibrate it densely, smoothing the surface. After pouring, cure for at least 3 days, avoiding trampling or applying loads during this period to ensure full development of concrete strength.

By following these methods, issues such as leakage and cracking in house prefabricated panel joints can be effectively resolved, extending the service life of the structure. The appropriate solution should be selected based on the actual situation, and construction quality should be strictly controlled.