14th May 2024 -

As the demand for improved sound insulation grows, soundproof plasterboard emerges as a versatile solution. Below, we look at the structural benefits of soundproof plasterboard, exploring its composition and installation methods. We examine how it enhances acoustic comfort, impact and fire resistance and dimensional stability.

What is soundproof plasterboard?

Also known as acoustic plasterboard or sound insulation plasterboard, it is blue-facing and manufactured to reduce sound transmission through wall and ceiling spaces. Unlike standard drywall, it features a unique multi-layered construction of sound-absorbing materials within its core.

The core consists of dense, high-performance insulation materials like mineral wool or recycled cotton fibres. These materials are sandwiched between 2 sturdy layers of gypsum plasterboard. This creates a block barrier that prevents sound waves.

Some varieties of soundproof plasterboard may also include a viscoelastic damping layer. The layer further boosts its acoustic insulation properties by converting sound energy into heat, minimising sound transmission. This allows soundproof plasterboard to significantly reduce both airborne and impact noise. 

4 structural benefits of soundproofing plasterboard

Sound insulation board offers various structural benefits that contribute to overall building performance and safety. Here, we outline these key structural benefits.

1. Increased structural integrity

Soundproof plasterboard’s dense, multi-layered construction results in greater rigidity and resistance to impact forces. The additional structural integrity improves load-bearing capabilities. This makes it suitable for applications that require more support, such as load-bearing partition walls or ceiling systems.

2. Stability and dimensional accuracy

Overall, soundproof plasterboard is less susceptible to warping and sagging over time. It ensures that wall and ceiling surfaces remain flat and level. Dimensional stability is crucial for maintaining the integrity of finishes like tiles, plaster or drywall joint compounds.

3. Fire resistance and safety

Some acoustic insulation plasterboard materials are formulated with fire-resistant materials like mineral wool or glass fibres in their core. These materials act as excellent thermal insulators, slowing the spread of flames.

Also, some soundproof plasterboards are rated for specific fire resistance levels. This makes them ideal for use in fire-rated assemblies and meeting building code requirements for fire safety.

4. Impact and moisture resistance

The multi-layered construction offers improved resistance to impact forces and moisture damage. Therefore, it is suitable for use in areas prone to high traffic, moisture or potential impact. This includes spaces such as bathrooms, utility rooms and commercial spaces.

How thick are soundproof plasterboards?

Soundproof plasterboard is available in different thicknesses to align with acoustic and structural requirements. Plasterboard thickness plays a crucial role in determining its sound insulation performance and structural integrity. Below are some general guidelines to consider.

Standard thicknesses

  • 12.5mm (1/2 inch): This is the most common thickness for standard residential applications for basic sound insulation requirements.
  • 15mm (5/8 inch): Slightly thicker than the 12.5mm boards, these provide moderate sound insulation suitable for multi-family dwellings and home offices. 
  • 18mm (3/4 inch): Offering improved acoustic performance, 18mm boards are recommended for areas with higher noise levels. For example, home theatres, music studios or proximity to busy streets.
  • 25mm (1 inch) or thicker: These heavy-duty boards provide superior sound insulation and are ideal for professional recording studios and auditoriums.

Application recommendations

  • Residential dwellings: For general living areas like bedrooms, living rooms, and corridors, 12.5mm or 15mm is sufficient to reduce noise transfer between rooms.
  • Home offices: To create a quieter environment for work or entertainment, 15mm or 18mm boards are recommended. This will depend on the desired level of sound insulation.
  • Multi-family dwellings: In apartment buildings or attached housing units, using 18mm or thicker soundproof plasterboard can significantly reduce noise transfer between adjacent units. 
  • Home theatres: For dedicated home theatres where optimal acoustic performance is essential, 18mm or 25mm (or thicker) soundproof plasterboard is advised. 

How to install sound plasterboard

Maximising the effectiveness of acoustic board systems requires careful installation. Proper techniques during installation are essential to ensure the material achieves full acoustic performance and maintains structural integrity. The following outlines key installation steps and factors to follow.

Installation steps

Framing: Construct framing using resilient metal channels or double rows of staggered studs. This framing technique minimises sound transfer through the structural elements by creating a disconnected path for vibrations.

Insulation: Fill all cavities between studs with high-density insulation materials like mineral wool or fibreglass batts. These insulation materials enhance sound absorption (sound deadening) by trapping sound waves and offer thermal insulation.

Staggered joints: When installing multiple layers, stagger the joints between adjacent sheets to minimise potential sound leakage paths. Continuous joints create a direct path for sound to travel through the assembly.

Sealant application: Apply acoustic sealant or gaskets around all edge and joint areas to create an airtight assembly and prevent sound flanking. Sound flanking occurs when sound skirts around the soundproof barrier through gaps or openings.

Mechanical fastening: Use drywall screws or nails, ensuring proper spacing and depth to avoid compromising the board's integrity. Incorrect fastener placement or over-driving will weaken the board's structure.

Isolation techniques: Incorporate sound isolation clips, furring channels or resilient sound bars to separate the plasterboard from the structural framing. This separation prevents the direct transfer of vibrations between the board and framing.

Structural considerations

Fastener scheduling: Follow manufacturer guidelines for fastener spacing to ensure adequate structural support. Improper fastening will lead to sagging or cracking of the boards.

As a general guideline, fasteners for walls should be spaced 200mm - 300 mm (8-12 inches). For ceilings, fasteners should be spaced every 150mm - 200mm (6-8 inches).

Board orientation: Install soundproof plasterboard with a long dimension perpendicular to framing members for increased rigidity and spanning capabilities. The orientation maximises the board's strength and minimises deflection.

Framing support: Provide sufficient framing members and bracing to accommodate the additional weight of thicker soundproof plasterboard. This is particularly important in acoustic plasterboard ceiling projects. Inadequate framing leads to sagging or collapse.

Joint reinforcement: Use specialised joint tapes or fibre-reinforced compounds to reinforce joints and improve overall board stability. It helps prevent cracks or joint separation over time.

Impact resistance: Consider using impact-resistant soundproof plasterboard in areas prone to damage, such as high-traffic zones or commercial spaces. These boards have added durability to withstand accidental impacts.

Fire-rated assemblies: When constructing fire-rated wall or ceiling assemblies, follow specific system designs and installation requirements to maintain the intended fire resistance rating. Improper installation compromises the structure’s fire resistance.

Does soundproof plasterboard require maintenance?

Yes, proper maintenance and timely repairs are essential to ensure its continued structural integrity. Different applications may require specific maintenance approaches. Recognising signs of damage is key to taking appropriate actions.

Residential applications

In residential settings, acoustic boards for walls and ceilings should be inspected annually. Inspections should also take place after renovation work for any signs of impact damage, cracks or joint separation.

Minor hairline cracks can be repaired using joint compound and reinforcing mesh tape. For larger cracks or holes, cut out the damaged section and replace it with a new sheet of soundproof plasterboard. 

Commercial applications

For high-traffic or industrial environments, plasterboard soundproof boards may be subjected to increased wear and tear. Regular inspections should be conducted every 6 months to identify areas of impact damage, moisture intrusion or delamination.

Promptly fix or replace damaged sections to maintain the assembly's structural integrity and acoustic performance.

Signs for replacement

While minor repairs can address localised issues, extensive damage may require complete replacement of the soundproof plasterboard. Signs that replacement may be required include the following.

  1. Widespread cracking or delamination: Extensive cracking or separation of panel layers can compromise its structural stability and acoustic properties.
  2. Significant impact damage: Large holes or areas of severe impact damage may be too extensive for localised repairs. This could affect the overall performance of the assembly.
  3. Water damage or mould growth: Prolonged exposure to moisture can cause swelling, warping and potential mould growth. It can weaken the board's structure and pose health risks.
  4. Age and deterioration: Noise insulation plasterboard becomes brittle or loses its acoustic properties because of ageing and exposure to environmental factors. Replacement may be necessary to maintain optimal performance.

With proper installation and maintenance, soundproof plasterboards have an average lifespan of 20-30 years in residential spaces. In high-traffic commercial environments, the lifespan is estimated at 10-15 years because of increased exposure to potential damage.

Is soundproof plasterboard available at Building Materials Nationwide?

We supply a wide selection of plasterboard soundproofing boards suitable for various applications. Our range includes different thicknesses designed to optimise acoustic performance and structural integrity. Whether you need soundproof plasterboard for residential or commercial projects, our top-quality products ensure lasting performance.

Trade customers benefit from opening a trade account with us. We provide access to fast UK delivery options, competitive trade pricing and personalised account management. Our dedicated team is ready to help you with a seamless purchasing experience. Spend a few moments signing up today or contact us to learn more.

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