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If you’re suffering from unwanted noise from above or below a room, one of the best options may be to soundproof a ceiling to acquire a more peaceful life.

No matter the purpose of the building, whether residential, a commercial building or factory, noise pollution is a nuisance.

In many cases, it can become a health concern.

If you have unwanted noise coming from above, most people will have no idea where to start when it comes to soundproof a ceiling.

Like many budding DIYers, they’ll most likely get their information from a variety of sources online, and in and amongst the facts, fiction and misinformation, they’ll end up even more confused than before they started.

Although effective soundproofing should be carried out by an experienced installer, it is possible to gain a pretty good grasp of how soundproofing principles work and achieve fairly acceptable results with a bit of research.

The best place to start is to learn more about the ways in which sound is produced, how it reacts to various environments and how you can lessen the effects of the sound in that environment.

For starters, most people are unaware that sound is in actual fact a form of energy.

Sound travels from the source and during the distance it travels causes vibrations whenever it hits air or any solid objects in its path.

This process causes soundwaves which are converted deep inside the ear via specialised cells called “hair cells”.

Sound vibrations cause these cells to bend slightly, at which point are converted into electrochemical signals that are interpreted as sound by the brain.

So the process of soundproofing is to effectively reduce the soundwaves produced, which lessens the noise levels created.

In this article, we’ll cover various ways to effectively soundproof a ceiling.

This includes key principles that will empower you and give greater knowledge and understanding of how to get the best results possible.

Understand Your Objectives

Like any soundproofing project, firstly ask yourself what the key objectives are.

This may sound obvious, but once you clarify exactly what you want to achieve, the rest becomes much clearer.

Firstly, what is the source of the nuisance noise, where is it coming from and how is it reaching you?

If the noise is coming from the floor above, it could be footsteps on a hard surface floor such as hardwood or floorboards.

Perhaps you have inconsiderate neighbours who play loud music through a hi-fi system or have a subwoofer producing deep, low frequency bass which is vibrating throughout your room from above.

Or maybe a kids room in your own home is not sufficiently soundproofed and you can hear the children playing and jumping around upstairs?

There could be an endless number of reasons why it’s time to soundproof a ceiling in your premises.

Whether the unwanted sound coming through the ceiling is due to impact noise, structural or airborne sound, you know it’s time to tackle it.

The correct approach is quite simple.

If the noise is coming from the floor above, downwards, then ideally it would be the floor above that would be treated. Not always possible I know, but that is the correct approach as this will arrest the noise at source before it has a chance to use the structure of the floor / ceiling assembly to move through from top to the bottom..

If the noise is coming from below, upwards, it is ideally the ceiling within that room which will need acoustically treating.

Identify Weak Points

The golden rule to effective soundproofing is that your acoustic treatment is only as good as your weak points.

Always keep in mind that sound travels at amazing speeds, in excess of 340 metres (1200 feet) per second and will always exploit the path of least resistance.

Much like water, if your ceiling has clear weak points and places where it can pass through, it will.

It is therefore vital that your approach to soundproofing is foolproof and mitigates any chance of air and soundwaves passing between points A and B. Any chances of trickle-through will ruin your hopes of a quiet life and reduced noise from above.

So it pays to check every aspect of the ceiling structure you intend to soundproof for weak points or places that will cause problems.

Types of Noise

Airborne

Airborne noises are defined as sounds transmitted by the air, like music or speech for example.

These types of soundwaves are carried by the air until they impact something solid, like a floor, ceiling, wall or a piece of furniture.

In the case of a ceiling or floor above, the sound collision sends vibrations through the floor and into the space below, or through the ceiling and into the space above.

Structural Airborne

As the name suggests, structural sounds are a result of impact or a vibration against a part of a building, which results in the sound radiating from the adjacent surface.

Impact

Impact noise is a form of structure-borne sound that occurs when an object impacts on another, resulting in the transmission of sound.

The structural vibration caused by the impact results in sound being radiated from an adjacent vibrating surface.

A ceiling with floors above is a prime example of this.

Stomping feet, dancing, kids running up and down, heavy objects dropped or simply heavy footsteps produce impact sound which in turn travel through the structure.

Now this could be a direct passage which in this case would be straight down and out of the ceiling structure below.

Equally this could be lateral vibration through the structure and horizontally to the supporting walls on which the structure is connected.

This is typical flanking transmission which offers an indirect pathway for sound to move from A to B, and in effect structural airbourne sounds that are then heard in the room below.

Building Structures & Common Problems

To effectively soundproof any structure, especially a ceiling, it’s vital to understand the basics of building types and how they are fabricated.

The following questions may be a useful start they are:

1. How is the structure built and with what materials?
2. The structural layout of one room to another?
3. Establish the likely depth of the structure if possible.
4. Can you establish any additional structural supports such as Support Steels, I-Beams, Lintels?
5. What are the likely routes for services and pipes, soil pipes or soil stacks?
6. Lighting such as down lights or wiring which could weaken the acoustic integrity?
7. If cavities are in evidence within the construction, are they filled with anything?
8. Whether structural wall finishes are of solid plaster, framed, or a ‘dot and dab’ principle with a plasterboard finish and therefore somewhat hollow sounding?

This will help you to effectively diagnose how the source sound is moving from its origin to its end point.

Once you are armed with this knowledge, you’re far more likely to have identified the correct acoustic installation method required to eliminate the unwanted noise coming through the ceiling.

In most homes where floorboards are present, and ceilings are finished with drywall (plasterboard) and a plastered render, sound is able to transmit via direct passage.

The problematic sound will travel through the air, via gaps and holes, with the air present in any open cavities between the ceiling and floor joists acting like mini caves or like a drum, regenerating and amplifying the initial sound generated.

In many respects the structure itself will be the biggest concern and the likely cause of flanking transmissions, as talked about previously.

These transmissions can move directly through the floor/ceiling structure as well as possibly up and down any structural load bearing walls or steel supports for example.

They need to be identified and given consideration.

Soundproofing a Ceiling

Before embarking on soundproofing your ceiling, you need to first identify the type of substrate present and the likely weight factors that can be tolerated.

As this will more than likely entail working at increased height, ensure that you have all the necessary safety measures and precautions in place.

Ensure you have adequate levels of assistance to safely install the materials to be incorporated in your soundproofing solution.

It’s also important to work out what kind of depth tolerances are available to work within, most specifically, head height clearance or distances to the tops of window frames.

Possible restrictions due to details like cornice and rails.

This will clarify the type of build up needed to acoustically insulate within the space available and provide the necessary platform onto which to install the finishing system.

As you will have heard before, invariably with this type of acoustic installation there will be a mix of the differing approaches available.

These being a decoupling principle where feasible, absorption where possible, deflection with the addition of mass and density and the ever important thermal conversion with a layer of Acoustiblok 3mm Isolation Membrane to convert the energy into a less problematic heat energy.

Most Common Types of Construction

There are so many different types of ceiling construction.

We have all heard of vaulted, cathedral, pitched or shed, beamed or barrel, but here we have covered the most common types usually found and that have associated acoustic issues.

If you establish that your type of construction is not listed here, please contact us and we will be happy to help and advise.

Timber Joist Construction

It is always the case with this type of assembly that there will be some depth of cavity that can be filled with open cell material to offer a thermal benefit, but imperatively an absorptive level.

In many cases this may be accessible without removing one finish or another.

Do not overlook this as a basic principle.

Filling the cavity between ceiling and floor above adds no depth, so can be regarded as free or dead space and should always be filled where possible.

Not only will this principle absorb acoustic energy, but it will also prevent resonance and regeneration within an otherwise open space, just like a drum.

In many cases it may not be possible to gain access to the cavity however, it is greatly recommended to try your best to achieve this.

If not, there will always be a greatly increased chance of resonance and failure.

If the existing plasterboard can be removed to gain access, first fill between the joists with a dense open cell material.

The bottom of the joists will now be exposed and can be used as the frame to mechanically attach a flexible Acoustiblok 3mm Isolation Membrane.

If ceiling board/finish is already present and cannot be removed, a framing system typically of timber or metal will need to be created to the underside of the ceiling.

This creates a platform onto which differing materials can be attached to complete the new ceiling.

Much like a horizontal version of a batten or stud frame wall principle.

This new cavity space can then be filled with open cell material followed by a lining of an isolation membrane, such as Acoustiblok attached to the underside of the new framing system.

At this point it is possible to either finish the ceiling in one of two ways.

Either by introducing a dense finishing board of choice directly into the underside by way of mechanical fixing into the joists above.

Or alternatively, additional cross battens (resilient channels/top hat channels) can be installed, perpendicular to the joist/first batten.

This will further decouple the structure and provide a platform on which to attach the finishing board by way of mechanical linkage/fixings.

Another measure which is quite widely used is to incorporate a second dense finishing board with overlapping/staggered junctions to the first board, to add more mass.

However, this invariably does not add a huge increase in acoustic noise reduction, but does increase the overall weight. So be sure of correct engineering calculations.

All heads of mechanical fixings should be countersunk and a nib of Acoustiblok Acoustic Silicone Sealant applied to the head to soften impact and flanking transmission as much as possible.

Block & Beam Construction

This structure will require a framework typically of timber or metal to be built to the underside of the ceiling, which then creates a platform onto which to attach differing materials to complete the new ceiling.

A little like a horizontal version of a batten or stud frame wall principle.

Suspended Ceiling/Acoustic Tiles

This structure would typically require a framework of timber or metal to be built to the underside of the existing structure which then creates a platform onto which to attach Acoustiblok.

This will then acoustically defend as close to the structure as possible, attached to the original structure as in the above instructions, prior to drop rods or suspended ceiling frame system being introduced with brackets or acoustic clips.

Essential Finishing

To ensure your installation is sound tight, it is vital to use the correct acoustic sealants, acoustic caulks, jointing tapes and acoustic putty pads to seal and repair any penetrations and obvious holes or areas of weakness.

I hope that this will help with planning a project such as soundproofing a ceiling and offer a few ideas as to the types of acoustic problems, types of construction you may find and the differing approaches you may entertain.

And to finish this particular blog here for good measure are some acoustic essentials.

Types of Soundproofing Principles

Acoustic Isolation

Acoustic Isolation is the prevention of sound leakage or sound ingress, to or from a particular area into another.

For example from an external source, outside to inside, or from one room or dwelling into another room/dwelling.

This can incorporate multiple approaches depending on any given situation, however they will invariably be based around four key principles.

1. Deflection

Mass, dense materials built into a building’s fabric, in this case either the floor or the ceiling board to increase density and push back sound from where it came.

This principle is invariably always going to be used in some way or another, as simply the finishing board of choice for rigidity.

However, whilst this principle is good to use, one has to remember that the mass, dense materials obviously have rigidity which can and will work against you as a flanking pathway.

Certain sound waves will pass through the material and into whatever it is attached and keep on going.

In the case of a floor/ceiling assembly it is likely to be the vibration through the floor finish into the floor structure, maybe a joist and into the plasterboard ceiling board.

2. Absorption

Open cell materials that can allow sound waves to enter the material and slow down the energy thus reducing the sound power and sound pressure of the initial source.

Always a material/principle that is used as a part fill within any cavity/void created by a framing system so in this case in between the joists.

The depth is going to be dictated by the depth of the structure or materials used to create the cavity – depth of joists, battens or stud type of frame.

Whilst useful to part fill any dead space to offer some sort of absorption and possible thermal benefit, this type of material really has to be super thick to achieve any higher levels of sound insulation, especially with lower frequency sound waves, which invariably defeats the object as it massively increases the thickness of the entire assembly.

However, if you have the chance to incorporate some thickness of absorption into the build, it is good to do so not only for sound absorption but critically to prevent any additional acoustic resonance or regeneration that would happen in a cavity that is left as a complete open void.

A bit like small caves… big no no!

3. Conversion

When sound waves come into contact with a membrane such as Acoustiblok, it vibrates the molecules of the materials which in turn creates friction which is cleverly converted to a trace heat energy.

Thus the material works by converting a more problematic acoustic energy into a less problematic heat energy which is simply transferred through the material sideways to reduce flanking transmissions.

In any serious or advanced strategy to isolate sound this is an absolute must to work in tandem with the other principles.

At only 3mm thick, the depth of the materials are hardly noticed in the great scheme of things but the benefits to uplift acoustic performance are immense.

4. Decoupling

Separation and decoupling of one side of the assembly to the other by way of a batten or resilient channel invariably installed perpendicular to the main frame and sometimes in conjunction with isolation bracket or clip in which to house the batten.

The principle of this not only reduces the direct mechanical fixing/linkage of the system therefore reducing the resulting flanking transmissions within the rigidity of the structure, but also provides an opportunity for a service chamber and a structural platform on which the chosen finishing system can be mechanically attached.

Acoustic Calibration

Acoustic Calibration is to balance or equalise the internal acoustics within a room to optimise quality of sound which will improve the listening experience.

Calibrating a room to reduce reverberation and distortion to achieve cleaner, audible and balanced sound waves can incorporate a number of differing systems or solutions.

But they will all tend to work on the basic principle of increasing absorption within the room and specifically the surfaces such as walls, floor, ceiling and therefore reducing reflection, deflection, regeneration.

1. Absorber Panels

AcoustiCloud Ceiling and Wall Panels

2. Baffles

A sound baffle is a construction or device which reduces the strength (level) of airborne sound.

Sound baffles are a fundamental tool of noise mitigation, the practice of minimising noise pollution or reverberation.

3. Diffusers

Diffusers are used to treat sound aberrations, such as echoes, in rooms.

4. Isolators

Vibration isolators often referred to as ‘spikes’ not only reduce vibration, but also lessen noise by preventing unwanted regeneration/resonance.

5. Soft Finishes

Soft Furnishings to surfaces such as carpets where appropriate, wall fabrics, drapes, curtains and soft furnishings such as seats, sofas, cushions and rugs can all help absorb sound energy.

Applying Correct Construction Techniques

Use the right construction techniques and materials, or a mixture of all the available options for the best possible outcome.

This is where an understanding of the problem and the situation you have will start to dictate the type of solution and materials you can use.

At this point you can start to see a return to previous questions, but will now be able to determine the correct approach.

Deflection

Use of differing mass and dense materials usually as the main structure and finishing materials.

Materials

• Concrete – typical wall and floor construction
• Masonry – typical wall construction
• Sand/Aggregates
• Mass Loaded Vinyl – rubber impregnated with mass to increase weight and density
• Plasterboard – differing thicknesses and densities depending on the stiffness and purpose and often applied in multiple layers to achieve higher ratings
• Dense sheet materials – ply, particle board

Absorption

Use of differing open cell materials within cavities or open spaces which allow for sound to be absorbed.

Materials

• Open Cell Fibres – natural fibre, mineral wool, stone wool
• Soft Furnishings – quilt or blanket
• Thermal Conversion
• Materials
• Uniquely Acoustiblok – as sound waves impact, the molecules of the membrane vibrate causing friction which in turn converts to heat. Simple and very thin with the highest acoustic effect mm for mm. Converting a problematic sound energy into a less problematic trace heat energy.

Decoupling

Use of system/materials to separate the mechanical linkage of the structure to minimise the direct connection from the front to the back/one side to the other.

Materials

• Resilient Channels – secondary decoupling usually used from source side
• Acoustic Clips/Brackets
• Staggered Stud Construction as an example with timber/steel stud