FLOOR SOUND INSULATION: BITUMEN MEMBRANE AND POLYESTER FELT SILENT FLOOR BYTUM
Floor sound insulation for timber and composite concrete floor structures
SILENT FLOOR BYTUM is acoustic insulation for floors that works according to the mass-spring-mass principle: the elastoplastomeric bitumen membrane and polyester felt act as a resilient layer between the structural floor slab and the screed, dissipating the energy transmitted by impact. It reduces impact sound by 20 dB (ISO 10140-3) on CLT floor slabs. The bituminous compound naturally seals around fastening systems, maintaining the watertightness of the build-up.
Installation is possible either from above during screed application or from below in the presence of a suspended ceiling, on timber, masonry and composite concrete floors.
Technical data and composition of SILENT FLOOR BYTUM acoustic insulation for floors
The membrane consists of an elastoplastomeric bitumen waterproofing layer bonded to a polyester fibre felt made from post-consumer recycled material. The 5 mm thickness and dynamic stiffness s' of 27 MN/m³ (EN 29052-1) classify the product as a resilient layer for floating screed systems.
Key technical features:
— Impact sound reduction ΔLw: 20 dB (ISO 10140-3)
— Theoretical ΔLw estimate: 27.7 dB (ISO 12354-2, m' = 125 kg/m²)
— Dynamic stiffness s': 27 MN/m³ (EN 29052-1)
— Compressibility class: CP2 (EN 12431)
— Thickness: 5 mm · Surface mass: 1.2 kg/m²
— Compression CREEP: ≤ 1 mm (EN 1606)
— Water vapour permeability Sd: > 70 m
Is SILENT FLOOR BYTUM compatible with floor sound insulation systems on CLT floor slabs?
Yes. Tests carried out by the University of Northern British Columbia document an AIIC improvement of 18 to 25 dB depending on screed thickness (38–100 mm) on a 139 mm CLT floor slab.
For a complete floor build-up with a 60 mm screed, Akustik Center Austria laboratories — Holzforschung Austria measured Ln,w(Cl) = 42 (0) dB and IIC = 67 (ISO 10140-3), with airborne sound reduction index Rw(C;Ctr) = 60 (-1;-4) dB (ISO 10140-2).
How does a double-layer acoustic insulation system for floors work, and when should it be used?
The double-layer configuration of SILENT FLOOR BYTUM, with opposing felt layers, reduces dynamic stiffness from 27 to 14.5 MN/m³ and increases the theoretical ΔLw estimate to 31.6 dB (ISO 12354-2, m' = 125 kg/m²).
The double-layer configuration is used when the floor build-up must withstand high loads or when higher acoustic performance is required. Installation requires a continuous SILENT EDGE perimeter strip around the entire perimeter, as any interruption creates an acoustic bridge that compromises system performance.
SILENT FLOOR BYTUM for floor sound insulation of existing floors: is it suitable for renovation projects?
Yes. On-site measurements on composite concrete floor slabs recorded L'n,w values between 55 and 58 dB (UNI-EN 10708-3/ISO 717-2) for floor build-ups with sand-cement screeds and lightweight screeds.
The elastoplastomeric bituminous compound makes SILENT FLOOR BYTUM durable over time and compatible with fresh concrete. In applications using timber-concrete connectors, the membrane prevents screed leakage, a key feature for floor sound insulation of existing floors in historic or prestigious buildings where floor build-up thickness is limited.
Documents
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Technical data sheets
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Technical Manual
SILENT FLOOR BYTUM
| CODE | H
[m]
|
L
[m]
|
s
[mm]
|
A
[m²]
|
pcs./pallet |
|---|---|---|---|---|---|
| SILFLOORBYT5 | 1.05 | 10 | 5 | 10.5 | 20 |
Product specifications
SILENT FLOOR BYTUM
Supply and installation of resilient underscreed foil, in bitumen and polyester felt, type SILENT FLOOR BYTUM.
Properties
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Thickness [mm]: 5
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Density ρ [kg/m^3]: 300
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Apparent dynamic stiffness s’t [MN/m^3]: 7
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Apparent dynamic stiffness s’t double layer [MN/m^3]: 4
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Dynamic stiffness s’ [MN/m^³]: 27
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Double layer dynamic stiffness [MN/m^3]: 14,5
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Compressibility class: CP2
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Double layer compressibility class: CP3
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Impact sound pressure level attenuation Δlw [dB]: 20
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Impact sound pressure level attenuation layer Δlw double layer[dB]: 21
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Water vapour transmission Sd[m]: >100
Description
Resilient underscreed foil designed to enhance impact noise insulation and increase the overall soundproofing performance of the finished floor slab.
The product consists of a waterproofing elastoplastomeric bitumen membrane bonded to a polyester fibre felt made from post-consumer recycled materials, confirming its sustainable nature.
Its composition and structure make it suitable even for heritage or high-value buildings, where preventing screed seepage is crucial, especially in hybrid systems using timber-to-concrete connectors.
The bituminous compound allows the membrane to seal effectively around fastening elements, ensuring excellent watertightness even in the presence of localized perforations. It can be effectively combined with cylindrical-shank, double-thread, and self-drilling tip connectors, such as CTC type.
The material is recyclable, rot-proof, insoluble in water, and non-irritating to skin, eyes, or respiratory systems. It does not contain substances harmful for people and the environment.
Installation
The membrane is typically applied in new constructions or renovation works, following the proper procedures for building a floating screed system.
To ensure optimal acoustic performance, the resilient layer must be installed continuously: any interruption may create acoustic bridges.
All joints must be sealed using FLEXY BAND, EASY BAND, or SPEEDY BAND sealing tape. Further details regarding installation can be found in the specific instructions provided by the supplier
