Only The Best Acoustic Supplies Can Bring Peace And Quiet

How Retrofit Soundproofing Can Improve Existing Buildings

Unwanted noise can affect homes, offices and commercial buildings of any age. Conversations may pass through lightweight partitions, footsteps may travel between floors, traffic may enter through windows and mechanical equipment can transfer vibration into the structure.

Retrofit soundproofing involves improving an existing building rather than incorporating acoustic separation during its original construction.

A retrofit may target one wall, floor or ceiling, or it may involve several connected parts of a room. The correct approach depends on the type of noise, the existing construction and the route through which sound is travelling.

Soundproofing can reduce transmission, but it cannot guarantee complete silence, total privacy or the removal of every distraction.

Newer Buildings Are Not Always Quieter

The age of a building does not determine its acoustic performance.

An older masonry property may have substantial walls but lightweight floors, poorly sealed windows or connected chimney structures. A newer office may use lightweight partitions that stop at a suspended ceiling, allowing conversations to travel through the shared void above.

Acoustic performance can be influenced by:

• The mass and construction of separating surfaces
• The depth and treatment of cavities
• Structural connections between rooms
• Doors, windows and ventilation openings
• Service penetrations and electrical fittings
• The quality of the original workmanship
• Alterations made since the building was constructed

A retrofit project should therefore begin with an assessment of the actual property rather than assumptions based on its age.

Identify the Type of Noise

Most soundproofing projects involve airborne noise, impact noise, structure-borne vibration or excessive reverberation.

Airborne noise

Airborne noise travels through the air before reaching a wall, floor, ceiling, door or window. Common examples include:

• Conversations and telephone calls
• Televisions, music and gaming systems
• Traffic, trains and aircraft
• Office equipment and machinery
• Noise from neighbouring properties or businesses

Reducing airborne noise generally involves adding suitable mass, improving airtightness and creating separation between layers of the construction.

Impact noise

Impact noise is created through direct contact with the building. Footsteps, moving chairs, dropped objects and exercise equipment can send vibration through floors, walls and ceilings.

Impact noise is usually best treated close to its source with a resilient floor layer, acoustic underlay or floating floor system.

Structure-borne vibration

Speakers, pumps, air-conditioning equipment, machinery and other systems may transfer vibration directly into floors, walls or supporting frames.

Anti-vibration mounts, isolated bases or changes to the way equipment is supported may be required. Adding wall panels or acoustic foam will not stop vibration travelling through the structure.

Echo and reverberation

Hard floors, glazed partitions, exposed ceilings and smooth walls can cause sound to reflect repeatedly within a room.

This is an internal acoustic problem and is normally treated with sound absorption rather than conventional soundproofing.

Soundproofing and Sound Absorption Serve Different Purposes

Soundproofing helps reduce noise passing from one room or property to another. Sound absorption reduces echo and reverberation within the same space.

Absorption products may include wall panels, ceiling rafts, acoustic screens and certain curtain systems. They can improve speech clarity and reduce the build-up of reflected sound.

They should not be relied upon to block conversations, traffic, music or footsteps through walls, floors or ceilings.

A room may require both approaches. A meeting room, for example, may need soundproofing for privacy and absorption to make speech clearer inside the room.

Find the Main Transmission Path

The surface where noise sounds loudest is not always the route through which it first entered.

Potential transmission paths include:

• Walls and lightweight partitions
• Floors and ceilings
• Suspended ceiling voids
• Raised access floors
• Timber joists and structural beams
• Doors and door frames
• Windows and glazing
• Ventilation ducts and grilles
• Pipes, cables and electrical openings

Sound that travels around the main separating surface through connected parts of a building is known as flanking transmission.

For example, an office partition may appear substantial but stop at the suspended ceiling. Conversations can then pass over the partition through the shared ceiling void.

Similarly, upgrading a domestic party wall may provide limited improvement if sound continues through the adjoining floor or ceiling structure.

Retrofitting Wall Soundproofing

Wall soundproofing may help reduce voices, television, music and workplace noise passing through a separating wall.

Depending on the original construction, a retrofit system may include:

• Acoustic insulation within a cavity
• Resilient bars or isolation clips
• An independent supporting framework
• Dense acoustic boards
• Flexible sealing around perimeter joints

The correct system will depend on whether the wall is masonry, blockwork, timber stud, metal stud or another construction.

JCW Silent Board Plus may form part of certain wall or ceiling systems, but no single board should be regarded as a complete solution.

Wall linings also reduce the usable dimensions of the room. Sockets, radiators, skirting boards, door frames and fitted furniture may need to be adjusted.

Retrofitting Floors and Ceilings

Noise between storeys may involve both airborne and impact sound.

Where the upper floor can be accessed, a suitable floor soundproofing system may use:

• An acoustic underlay
• A resilient floor deck
• A floating floor construction
• Acoustic insulation between joists
• Additional mass within the floor build-up

Floor systems can increase the finished level and affect door clearances, thresholds, stairs, skirting boards and fitted furniture.

Where the floor above cannot be treated, ceiling soundproofing may help. Possible systems include acoustic insulation, resiliently mounted boards or an independent ceiling.

An independent ceiling can provide useful structural separation but reduces the available room height. Lighting, alarms, sprinklers, ventilation and cable routes must also be incorporated carefully.

Ceiling treatment may reduce the direct path while some impact vibration continues through surrounding walls and structural connections.

Doors and Acoustic Privacy

A lightweight or poorly sealed door can weaken an otherwise substantial room enclosure.

A soundproof door may be appropriate where the doorway has been identified as a significant transmission path.

The performance of the complete doorset depends on:

• The mass and construction of the door leaf
• The frame
• Perimeter seals
• The threshold or drop seal
• Accurate alignment
• The quality of installation

A specialist door will provide limited benefit if most of the noise is travelling through the walls, ceiling void, raised floor or ventilation system.

External Noise, Windows and Ventilation

Road, rail and aircraft noise often enters through windows and ventilation openings rather than through the main external wall.

The acoustic performance of a window depends on:

• The thickness and specification of the glass
• The spacing between panes
• The frame construction
• The condition of perimeter seals
• Opening sections and trickle vents

Not all double-glazed windows provide the same sound reduction. Secondary glazing may be suitable in some properties because it creates a larger cavity between separate panes.

Ventilation openings should not simply be blocked. Homes and workplaces require adequate airflow for indoor air quality, moisture control, cooling and safe operation.

Acoustic vents, attenuators or redesigned duct routes may be needed where ventilation is an important sound path.

Retrofitting Office Soundproofing

Office soundproofing may help reduce conversations passing between meeting rooms, private offices and adjoining businesses.

For confidential rooms, the complete enclosure should be considered, including:

• Walls and glazed partitions
• Doors and thresholds
• Suspended ceiling voids
• Raised access floors
• Ventilation ducts
• Cable and service openings

Improving one visible partition may not provide sufficient privacy if sound can bypass it through a shared ceiling or floor void.

Acoustic Pods and Open-Plan Offices

Acoustic pods can provide enclosed areas for telephone calls, focused work and smaller meetings. Their performance depends on the construction of the walls, glazing, door, seals and ventilation system.

A pod should not automatically be assumed to provide complete confidentiality. Product specifications and the sensitivity of the conversations should be considered before it is selected.

In open-plan offices, acoustic screens, ceiling treatments and absorptive panels can help control local speech and reverberation.

Acoustic curtains may absorb some sound and divide areas visually, but they do not normally provide the same room-to-room isolation as a fixed, sealed wall.

Retrofitting Soundproofing at Home

Home soundproofing may help with:

• Voices and television through party walls
• Footsteps and activity between floors
• Noise entering bedrooms from hallways
• Home offices and study areas
• Music, gaming and entertainment rooms
• Traffic and other external noise

In flats and converted properties, several households may share walls, floors, beams, ceiling voids and service routes.

Our guidance on flat and HMO soundproofing explains some of the additional considerations found in multi-occupancy buildings.

Lease conditions, landlord permission, fire compartmentation and building requirements may also need to be checked before work begins.

Seal Gaps and Service Penetrations

Small openings can weaken the performance of a wall, floor or ceiling system.

Common weak points include:

• Pipe and cable openings
• Electrical sockets
• Board edges and perimeter joints
• Gaps beneath skirting boards
• Openings into floor and ceiling voids
• Door and window frames

A flexible acoustic sealant can help close suitable perimeter joints as part of a complete soundproofing system.

Sealant alone will not soundproof a weak partition. Its role is to close small air paths that could otherwise undermine the wider construction.

Service penetrations may also require tested fire-stopping treatment. Acoustic alterations must not compromise the required fire performance of the building.

Installation Quality Matters

Retrofit systems can underperform when they are installed incorrectly.

Common problems include:

• Rigid fixings bridging resilient components
• Unsealed board edges
• Compressed acoustic insulation
• Floating floors touching surrounding walls
• Partitions stopping at suspended ceilings
• Untreated sockets and service openings

Some straightforward systems may be suitable for an experienced DIY installer. Independent walls, floating floors, suspended ceilings, acoustic doors and ventilation alterations may require a competent tradesperson or experienced acoustic installer.

Set Realistic Expectations

Retrofit soundproofing can improve homes and offices, but it cannot guarantee complete silence, perfect concentration or total confidentiality.

The result will depend on:

• The source, level and frequency of the noise
• Whether it is airborne, impact-based or structure-borne
• The existing building construction
• The number and severity of weak points
• Flanking transmission
• The system and products selected
• The quality of installation

Low-frequency bass, aircraft noise, heavy impact sound and mechanical vibration can be particularly difficult to control.

The practical objective is normally to achieve a meaningful reduction while balancing acoustic performance with room dimensions, ventilation, access and project cost.

Plan a Targeted Retrofit Soundproofing Project

Before ordering soundproofing products, identify the noise source and establish whether the main route is a wall, floor, ceiling, door, window, ventilation opening or structural connection.

A targeted retrofit based on the building and transmission path is generally more effective than adding acoustic materials to every available surface.

Call Acoustic Supplies on 01204 548400 or contact the team online to discuss your soundproofing project.