Standard plasterboard closes a wall cavity and provides a smooth surface for decoration. What it does not do well is block sound — it is too lightweight to contribute significant mass to an assembly. Acoustic plasterboard is a denser, heavier variant of the same product that adds meaningful mass to a wall or ceiling at the point of finishing. It is the last layer in a high-performance assembly, and using it instead of standard board can contribute several decibels of additional sound reduction without adding construction depth or changing the installation method.
Acoustic plasterboard is specified in wall and ceiling systems where Part E of the Building Regulations must be met, or where a demanding acoustic performance target is required in a commercial or studio build. In these applications, every component in the assembly contributes to the final performance — and the plasterboard is one of those components.
How acoustic plasterboard works
Sound transmission through a wall or ceiling is governed primarily by the mass law: heavier elements vibrate less at a given sound pressure and transmit less energy to the other side. Standard plasterboard runs at approximately 8–9kg per square metre. Acoustic plasterboard typically runs at 12–15kg per square metre, depending on the product and board thickness. That additional mass, applied across the entire surface of a wall or ceiling, adds measurable improvement to the weighted sound reduction index (Rw) of the assembly.
The improvement from upgrading the plasterboard alone is typically 1–3dB Rw. This is modest compared to the larger gains achievable through decoupling or additional mass layers — but it is essentially free if you are using plasterboard anyway, and small dB gains at the specification stage are much cheaper than remediation after a pre-completion test.
Acoustic plasterboard is most effective when used in combination with other acoustic components: resilient clips and channels for decoupling, acoustic mineral wool for cavity fill, and acoustic membranes within the build for additional mass. The full assembly performance, not the individual component, is what matters for Part E compliance.
Typical use cases
- Separating walls between dwellings — the finishing layer on both sides of a party wall in new builds and conversions. Part E requires a minimum DnT,w + Ctr of 45dB for airborne sound; acoustic plasterboard contributes to meeting this target in correctly specified assemblies
- Separating floors — acoustic plasterboard on the ceiling below a separating floor adds mass to the ceiling element, contributing to both airborne and impact sound performance
- Commercial acoustic partitions — meeting rooms, practice rooms, and consultation rooms where Rw 45dB or above at the partition is required for speech privacy or noise control compliance (BS 8233)
- Home recording studio builds — used as the board layer in double-stud or resilient clip wall systems, where maximising mass in the finished assembly is part of the isolation strategy
- Replacement of standard board in existing assemblies — where a wall or ceiling is being re-boarded as part of a renovation, specifying acoustic rather than standard board is a low-cost upgrade
Technical notes
Acoustic plasterboard is evaluated as part of a complete wall or ceiling assembly — individual board test data is less useful than system test data. System-level Rw, STC, Dnt,w + Ctr, and Ln,w figures for tested assemblies are available on request for specification purposes. Part E of the Building Regulations sets minimum performance requirements for new dwellings and conversions: the correct assembly depends on construction type (timber frame, masonry, steel frame) and the specific separating element (wall, floor, ceiling). BS 8233 provides guidance targets for non-residential spaces. We can advise on the appropriate assembly for your project type and performance requirement.
What's the difference between acoustic plasterboard and standard plasterboard?
Standard plasterboard (12.5mm, approx. 8–9kg/m²) is designed for general wall and ceiling finish work. It provides no meaningful acoustic isolation contribution above the mass of the substrate it covers. Using it in a high-performance acoustic assembly does not undermine the system — it just leaves performance on the table that could be picked up for marginal additional cost.
Acoustic plasterboard (typically 12.5mm–15mm, 12–15kg/m²) achieves its additional mass through higher-density gypsum and in some products through added barium sulphate or similar dense fill. The installation method is identical; it is heavier to handle. When used in place of standard board in a resilient clip + acoustic fill assembly, it contributes additional Rw improvement that would otherwise require additional layers or greater construction depth to achieve.
The additional cost is modest — typically a small premium over standard board per sheet. For Part E or demanding commercial specifications, it is worth specifying. For a basic partition with moderate acoustic requirements, standard board is acceptable. If you are unsure which is appropriate for your build, describe your project and we'll advise on the right specification.