How to Make a Mezzanine in a Prefabricated House

Common methods for creating mezzanines in prefabricated houses include steel frame + ALC floor slab, steel frame + steel plate + surface concrete, TD-LOFT ultra-thin mezzanine system, etc. Among them, the steel frame + cement pressure plate has been gradually phased out due to safety issues.

1. Steel Frame + ALC Floor Slab
Horizontal steel beams spaced no more than 1.2 meters apart serve as the load-bearing structure. Angle iron is welded to the sides, and 75-100mm thick ALC (autoclaved aerated concrete) panels are inserted, with gaps filled with mortar. The structural thickness of this solution is approximately 120-150mm, with a total thickness of about 22cm after decoration. ALC panels offer advantages such as light weight, sound insulation, and thermal insulation, but it is important to avoid drilling holes in the floor slab later to prevent damage to the internal structure and a reduction in load-bearing capacity.

2. Steel Frame + Steel Plate + Surface Concrete
Using steel beams as the load-bearing components, a checkered steel plate is laid and then covered with 50mm fine aggregate concrete, resulting in a total thickness of approximately 280mm. If a ribbed beam form (with closer spacing of steel beams) is used, the thickness can be reduced to no less than 200mm. This solution offers strong load-bearing capacity and is suitable for scenarios requiring heavy loads (such as equipment placement or densely populated areas), but it has a significant self-weight, necessitating confirmation that the original building structure can support the additional load.

3. TD-LOFT Ultra-Thin Mezzanine System
This system employs prefabricated dry construction methods, using corrugated steel plates as the load-bearing components and integrating decoration, waterproofing, fire resistance, and sound insulation functions. The completed thickness under normal spans is only 120mm, and it can be compressed to 100mm for spans less than 3.3m. Its advantage lies in its ultra-thin design that saves space, allowing direct laying of wooden flooring without the need for keel-fixed fire-resistant gypsum boards, making it suitable for prefabricated house renovations with strict height requirements.

4. Steel Frame + Expanded Perlite Slab (Supplementary Explanation)
The steel beam layout is similar to the ALC solution, but expanded perlite slabs are used as the floor slab material. Expanded perlite slabs offer light weight and fire resistance, but specific thickness and construction details need to be determined based on product specifications. Since the reference information does not fully explain its advantages and disadvantages, comprehensive evaluation based on material properties and engineering requirements is necessary in practical applications.

Precautions

• The steel frame + cement pressure plate has been gradually phased out by the market due to safety issues such as cracking and deformation after long-term use, and is not recommended.
• Mezzanine design should entrust a professional structural engineer to calculate the load, ensuring that parameters such as steel beam spacing and material thickness comply with safety regulations.
• Before construction, the load-bearing capacity of the original building structure (such as walls, beams, and columns) should be inspected to avoid structural damage caused by the additional weight of the mezzanine.