In modern building projects, acoustic comfort has become a key technical requirement. Reducing sound transmission—particularly impact noise between floors or adjacent rooms—is essential for meeting regulations and improving habitability.
Elastified Expanded Polystyrene (EEPS) has emerged as an enhanced version of traditional Expanded Polystyrene (EPS), specifically engineered to offer improved performance against vibrations and structure-borne noise.
Thanks to its modified structure and increased flexibility, EEPS functions as a high-performance acoustic insulating polystyrene, ideal for floating floor systems in residential, hotel and commercial developments.
What is Elastified Expanded Polystyrene (EEPS)?
Elastified Expanded Polystyrene is a variant of conventional EPS, produced through a controlled expansion process followed by a treatment that lowers its dynamic stiffness and increases its damping capacity.
This structural modification allows the material to better absorb impacts and vibrations, converting them into internal deformation energy.
The result is a lightweight, elastic and dimensionally stable material capable of significantly improving impact sound insulation while retaining the excellent thermal properties of EPS.
From a technical perspective, EEPS maintains a low thermal conductivity (λ ≈ 0.031 W/m·K) and achieves dynamic stiffness (SD) values of around 17–25 MN/m³, placing it among the most efficient solutions on the market for acoustic floating floor systems and comfortably meeting the requirements of the Spanish Building Code (CTE DB-HR).
Performance Against Impact Noise
Impact noise is produced by footsteps, dropped objects or vibrations transmitted structurally through floors and walls.
For this type of noise, the material’s dynamic stiffness is the determining factor: the lower the stiffness, the better the reduction of transmitted sound.
Elastified Expanded Polystyrene stands out due to its low dynamic modulus and excellent elastic recovery, which enable it to effectively dampen structure-borne sound waves.
When installed beneath a floor finish or within a floating floor system, it disrupts the acoustic bridge between the walking surface and the structural slab, substantially reducing perceived noise levels.
Tests carried out by manufacturers and European laboratories have demonstrated impact sound reductions of up to 25 dB, depending on the thickness and configuration of the construction system.
Advantages of Elastified Acoustic Insulating Polystyrene
Using EEPS as an acoustic insulating polystyrene provides numerous technical and construction-related benefits:
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High-performance impact sound insulation, ideal for meeting CTE DB-HR requirements (Protection Against Noise).
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Complementary thermal performance, preserving the insulating characteristics of traditional EPS.
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Low weight, facilitating installation and minimising load on the structural slab.
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High durability, with dimensional stability and resistance to moisture.
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Sustainability, as it is 100% recyclable and can be reintroduced into new EPS products.
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Compatibility with standard construction systems, such as concrete slabs, floating screeds and lightweight prefabricated systems.
Applications of Elastified Polystyrene in Construction
Elastified Expanded Polystyrene is primarily used in projects requiring acoustic improvement without significantly increasing system weight or thickness:
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Floating floors and screeds in homes, hotels, hospitals and office buildings.
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Renovation projects, where EEPS’s low weight enables upgrades without overloading existing structures.
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Perimeter strips and expansion joints to prevent acoustic bridges between vertical and horizontal elements.
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Behind partition linings and lightweight walls, combining thermal insulation with vibrational damping.
Its versatility makes it a suitable solution for both new-build projects and acoustic or energy retrofits.
Technical Specification and Standards
For specifiers and designers, the following aspects are essential when incorporating elastified polystyrene into a project:
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Applicable regulations: CTE DB-HR (airborne and impact sound insulation) and DB-HE (energy efficiency).
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Product certification: must comply with UNE-EN 13163 for expanded polystyrene products.
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Dynamic stiffness (SD): select the appropriate value depending on the floor type and acoustic requirements.
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Thickness and density: directly influence acoustic and thermal performance.
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Material compatibility: to be combined with anti-impact membranes, self-levelling screeds or certified floating floor systems.
At Polivas, we offer tailored technical support to determine the optimum density, thickness and system configuration of EEPS based on the specific needs of each project.
Examples of Use in Real Projects
In Mallorca, elastified expanded polystyrene has become a strategic choice for high-performance residential and hotel buildings.
Its installation within floating screed systems over structural slabs has enabled:
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Significant reduction of impact noise between rooms or storeys in hotel environments.
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Compliance with both national and regional acoustic regulations.
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Simultaneous improvement of thermal insulation in floor slabs.
Its low weight and ease of installation also make it particularly suitable for urban renovation projects, where speed and cleanliness of execution are key.
Conclusion
Elastified Expanded Polystyrene (EEPS) represents a technical advancement in acoustic insulating polystyrene, offering highly effective performance against impact noise while maintaining low weight, sustainability and thermal efficiency.
Thanks to its low dynamic stiffness and excellent elasticity, it stands out as one of the most balanced and efficient solutions for floating floors, slabs and interior partitions.
At Polivas, we support architects, engineers and contractors in integrating elastified expanded polystyrene systems into building projects across Mallorca, providing technical assistance, product documentation and solutions tailored to each construction typology.