Part E Acoustic Solution for Timber Joist Separating Floors: Using Noisedeck 32, Insulation, and Soundbreaker Bars

20th September 2024

Part E Acoustic Solution for Timber Joist Separating Floors: Using Noisedeck 32, Insulation, and Soundbreaker Bars

Addressing sound transmission between floors is crucial when constructing or renovating buildings, particularly in multi-level properties. Building Regulations Part E sets out requirements for sound insulation to ensure both airborne and impact sound levels are minimised between separating floors in residential or commercial properties.
One highly effective solution for timber joist separating floors involves the combination of Noisedeck 32, acoustic insulation, Soundbreaker resilient bars, and acoustic plasterboard. This article outlines how these components work together to meet and exceed sound insulation standards.

Direct Application of Noisedeck 32

Noisedeck 32 is an acoustic flooring board specifically designed for use in timber joist constructions. It provides structural integrity and significantly reduces impact noise transmission when applied directly to the joists. The Noisedeck 32 boards create an additional layer of mass, which helps to reduce the airborne sound passing through the floor structure.

To install Noisedeck 32:

Lay the boards directly on top of the timber joists.
Ensure the boards are laid in a brick bond pattern as a floating floor without being fixed directly into the joist to prevent sound bridging, which could reduce the effectiveness of the acoustic system.

Noisedeck 32

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Acoustic Insulation Between Joists

Filling the void between the joists with acoustic insulation is essential for further reducing airborne sound. Materials such as mineral wool or acoustic slab insulation absorb sound energy within the cavity, preventing it from passing through. We recommend using thickness 100mm and 60kg/m3 density slabs.

The key steps for insulating between joists include:

Cut the insulation to fit snugly between each joist, ensuring complete coverage with no gaps.
Choose insulation with a high density and sound absorption rating for the best performance.

DFM Acoustic Insulation 100mm

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Installation of Soundbreaker Resilient Bars

Resilient bars are vital for reducing sound transmission to the ceiling below. The Soundbreaker resilient bars are installed perpendicular to the joists, creating a decoupling system that isolates the ceiling from the floor structure. This prevents vibrations from travelling through the joists into the ceiling below, thus reducing both airborne and impact sound.

How to install Soundbreaker resilient bars:

Fix the bars directly to the underside of the timber joists.
Ensure the bars are installed correctly with the resilient edge facing downwards to maximise effectiveness.

Soundbreaker Resilient Bars

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Two Layers of Acoustic Plasterboard on the Ceiling

Finally, adding two layers of high-density acoustic plasterboard to the ceiling beneath the resilient bars further improves sound insulation. The plasterboard’s mass helps block airborne sound, while the resilient bars isolate it from the vibrations coming through the joists.

To install the plasterboard:

Attach the first layer of acoustic plasterboard directly to the resilient bars.
Stagger the joints of the second layer to reduce sound leakage, and screw the plasterboard in place.
Seal all joints and edges with acoustic sealant to ensure a complete sound barrier.

12.5mm Acoustic Plasterboard

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Conclusion

This combination of Noisedeck 32, acoustic insulation between the joists, Soundbreaker resilient bars, and two layers of acoustic plasterboard provides an effective solution for timber joist separating floors, meeting the requirements of Part E of the Building Regulations. By addressing airborne and impact sound, this system ensures improved acoustic performance and a quieter environment for occupants.

This approach is ideal for residential conversions, new builds, and renovations where noise control is a priority.