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How Polystyrene Underfloor Insulation Can Save You Money and Boost Comfort
Underfloor insulation is essential for creating warm, energy-efficient homes, and polystyrene is one of the best materials for the job. Its excellent thermal properties, combined with strength and moisture resistance, make it ideal for insulating floors while supporting structural loads.

Why Use Polystyrene for Underfloor Insulation?
Polystyrene insulation boards, especially extruded polystyrene (XPS), are commonly installed beneath floor slabs or between joists to prevent heat loss to the ground. Their high compressive strength ensures the insulation can bear heavy loads without compressing or degrading, which is critical for long-term performance.
Additionally, polystyrene’s moisture resistance prevents dampness and mold, a common problem in underfloor areas. This keeps floors dry and maintains indoor air quality.
Advantages of Polystyrene Underfloor Insulation
High compressive strength: Supports heavy floor loads and structural elements.
Excellent thermal insulation: Minimizes heat loss and reduces heating costs.
Moisture resistant: Prevents dampness and mold formation under floors.
Lightweight and easy to install: Speeds up construction and renovation projects.
Common Applications
Polystyrene underfloor insulation is used in residential and commercial buildings under concrete slabs, suspended timber floors, and especially in conjunction with underfloor heating systems to maximize heat retention and energy efficiency.
Conclusion
Using polystyrene for underfloor insulation delivers a cost-effective way to improve comfort and reduce energy bills. Its strength, durability, and moisture resistance make it a top choice for many building projects.