Insulation Materials for Factory-Prefabricated Houses

Common insulation materials for factory-prefabricated houses include rock wool, extruded polystyrene (XPS), polyurethane foam, phenolic foam, silicate, etc. When selecting, it is necessary to comprehensively consider fire performance, insulation effect, and cost requirements.

Common Types and Combustion Performance

Insulation materials are classified into four grades based on combustion performance:

• Grade A (Non-combustible): Such as rock wool and silicate, suitable for scenarios with extremely high fire protection requirements, such as high-rise buildings or public buildings. Rock wool is made from basalt, is heat-resistant, and has a low thermal conductivity coefficient, but it has a relatively high water absorption rate and needs to be used in conjunction with a waterproof layer.
• Grade B1 (Difficult to Burn): Such as phenolic foam and some modified polyurethanes, which self-extinguish when away from fire and are suitable for mid- to high-rise residential buildings. Phenolic foam has a high closed-cell ratio, excellent insulation performance, and a relatively low price (about 27 yuan per square meter), but it has low strength and needs to avoid external force impacts.
• Grade B2 (Combustible): Such as ordinary extruded polystyrene (XPS), whose drippings during combustion may cause secondary fires and are mostly used in low-rise buildings or areas with low fire protection requirements. XPS has a low thermal conductivity coefficient (about 0.028W/m·K) and high compressive strength, but its environmental performance is poor, and it easily releases harmful gases.
• Grade B3 (Flammable): Such as unmodified polystyrene foam, which has gradually been phased out and is only used in temporary buildings or non-fire-protected areas.

Special Application Forms

Some materials can adapt to different structural requirements through cast-in-place or prefabricated processes:

• Asphalt Perlite Insulation Board: It can be cast in place or prefabricated and is used for roof insulation layers, combining waterproofing and insulation functions, but it has a relatively large self-weight and requires structural reinforcement.
• Polyurethane Insulation Board: It is prefabricated in the factory and then directly installed, with high construction efficiency (about 80 yuan per square meter), but attention needs to be paid to joint treatment to avoid thermal bridges.

Cost and Selection Recommendations

There are significant differences in material prices:

• Rock wool costs about 145 yuan per cubic meter and is suitable for long-term fire protection requirements;
• Phenolic foam costs about 27 yuan per square meter, has high cost-effectiveness but generally poor durability;
• Polyurethane costs about 80 yuan per square meter, has excellent comprehensive performance but a relatively high cost.

When selecting, it is necessary to prioritize compliance with fire protection regulations (such as the Code for Fire Protection Design of Buildings GB50016), then determine the insulation thickness according to the climate zone (such as thicker materials are needed in cold regions), and finally balance performance and cost based on the budget. For example, XPS or polyurethane can be selected in cold regions in the north, while in hot and humid regions in the south, emphasis should be placed on the moisture-proof performance of materials.