Prefabricated Panels for House Decoration

Prefabricated panels cannot be directly plastered; base treatment is required first. Here is a detailed analysis:

I. Problems with Direct Plastering

1. Surface Flatness Issues
   Prefabricated panels are molded in factories, and while their surfaces are generally flat, there may be minor pores, mold release agent residues, or joint misalignments. These defects directly affect the adhesion of the plaster layer, leading to local hollowing or uneven surfaces. For example, mold release agent residues can form an isolation layer, preventing effective bonding between the plaster and the panel.
2. Material Property Limitations
   Concrete is dense and has low water absorption on its surface. Some prefabricated panels are enhanced with waterproofing or smoothing agents to improve durability. These additives further reduce surface roughness, resulting in insufficient mechanical interlocking between the plaster layer and the base, making it prone to detachment, cracking, or blistering. In actual cases, prefabricated panels that are directly plastered without treatment are likely to crack during the drying and shrinking process due to stress concentration.
3. Joint Treatment Challenges
   Prefabricated panels are connected through joints during installation. If these joints are not properly filled, direct plastering can cause the plaster layer to break at the joints. Minor displacements at the joints can also lead to the overall detachment of the plaster layer, especially in environments with temperature changes or vibrations.

II. Correct Construction Process

1. Surface Inspection and Cleaning
   Use sandpaper or a wire brush to smooth out uneven areas on the surface and remove dust from pores. Thoroughly clean surface oil and residues with water or a specialized cleaning agent (such as a mold release agent remover). If necessary, rinse with a high-pressure water gun and ensure complete drying. The drying time should be adjusted according to environmental humidity, typically not less than 24 hours.
2. Base Treatment
   Perform specialized treatment on the joints of the prefabricated panels: first, fill the joints with a specialized joint filler (such as an elastic polymer joint compound), ensuring a filling depth of not less than 5mm, and compact and smooth it with a scraper. After the joint filler dries, apply anti-crack fiberglass mesh tape (width not less than 100mm) at the joints to enhance crack resistance.

III. Usage Precautions
Prefabricated panels have structural safety hazards; their overall integrity is weaker than that of cast-in-place panels, and slight shaking can cause loosening or even detachment at connection points. Additionally, their leakage risk is significantly higher than that of cast-in-place panels. Therefore, prefabricated panels are not suitable for use in damp environments such as kitchens and bathrooms. If they must be used, additional waterproofing treatment (such as applying a permeable crystalline waterproof coating) and the installation of drainage channels are required.