Soundproof Ceilings to Stop Airborne and Impact Sound
If you live in a flat, or a property converted to accommodate multiple occupants ceiling soundproofing might be your only option when trying to reduce noise generated by your neighbours. Even if you live in detached property soundproofing your ceilings can be used to reduce the noise between living rooms and bedrooms, listening to a teenager playing computer games in there bedroom is not very relaxing after a day at work. Various solutions are available depending on what type of noise you are trying to stop, airborne or impact noise and how much height you can afford to lose in the rooms you are trying to soundproof. In this article you will find solutions to suit the most common noise problems in domestic properties, as well as how to soundproof a ceiling to meet current Building Regulations Part E.
Is it airborne or impact noise?
Airborne Sound – This occurs when a sound transfers directly from a source to the receiver. Typically this would be through small holes or openings in the construction, along ductwork, or through voids such as ceiling cavities. Airborne noises are conversation, TV noise, music, barking dogs.
Impact Sound – Impact noise is structural vibration, transmitted from a point of impact through a structure and experienced as radiated sound from a vibrating surface. This is commonly caused by an item hitting the floor, from where the impact results in vibrations being transferred through the buildings structure. The most common path for the noise is generally to the ceiling of the lower property or room. Impact noises are footfall, dropping items on the floor, children running.
Soundproof a ceiling by insulating the existing ceiling cavity
A majority of properties are built with plasterboard or lathe and plaster ceilings fixed onto wooden ceiling joists with floorboards or a chipboard floor laid over the joists, this type of construction creates a void or cavity. If you are trying to stop airborne sounds transferring through a ceiling you should look at insulating the cavity between the ceiling and floor. This method of soundproofing a ceiling is carried out on new build and converted properties to meet the current regulations. If you are soundproofing an existing ceiling and only have access from below you will have to remove the ceiling.
Use Acoustic insulation inside your ceiling voids to reduce airborne sounds
Whether you are insulating an existing ceiling or soundproofing a new build using an acoustic insulation slab between the joists is essential to achieve the required levels of soundproofing. Do not use thermal insulation rolls for this as they are low in density which means they will not block and absorb the airborne sounds.
Install DFM acoustic insulation slabs inside the ceiling cavities, the slabs are compressed to increase the density of the insulation which means they are suitable for using as an acoustic infill between the joists. DFM insulation is supplied in 1200mm x 600mm slabs, and they range in density from 45kg up to 140kg/m³, the slabs are also supplied in different thicknesses ranging from 25mm up to 100mm.
- DFM slab thickness - 25mm 50mm 75mm 100mm
- DFM density range - 45kg 60kg 80kg 100kg 140kg
Ceiling insulated with 100mm DFM acoustic insulation and soundbreaker bars, reduce airborne and impact sounds with this method of soundproofing.
Building Regulations stipulate that the insulation used between separating floors should be 100mm thick and have a density of 45kg/m³. Although using this density of acoustic insulation will help you meet the required Part E levels we would recommend using a higher density for most domestic soundproofing solutions. Compliance with regulations does not mean that sound will not transfer between rooms, if you want a higher level of soundproofing use the 100mm 80kg/m³ DFM slab, the higher the density the better the sound insulation performance, however the level of improvement does diminish with each increase in density, that is why we recommend the 80kg/m³ as it offers good levels of airborne sound insulation compared to the money you spend. Double the density does not equal double the performance, but it will mean twice the price. For more information on DFM acoustic insulation, click here.
Use acoustic hangers and create separation in the ceilings structure
As part of a ceiling soundproofing solution creating separation in the construction is vital to increase airborne and impact sound insulation. The best method of creating separation is to build an independent structure below the existing ceiling, this type of soundproofing can only be carried out if you have enough height in the room, as an estimate the ceiling height would drop by 6 inches, if you can not afford to lose this much room use an acoustic hanger to create the separation.
Attach soundbreaker bars to the underside of ceiling joists at around 350mm centres, hang acoustic plasterboard from the bars to reduce sound transmitting through the ceilings structure.
Soundbreaker bars will reduce sound transferring through ceilings
Soundbreaker bars are an acoustic hanger designed to be attached to the underside of the ceiling joists, the unique design of the soundbreaker bars reduces sound transmission through the ceilings structure, reducing impact and airborne sounds. Most new build and conversion projects use this type of acoustic hanger as part of the new separating ceiling construction. Plasterboard can be fixed directly onto the bars rather than into the ceiling joists, the bars separate the board from the joist and reduce surface area contact, they also absorb vibration reducing airborne and impact sounds transferring through the ceiling.
Use soundproof ceiling panels to block airborne noise
A quick and simple method of soundproofing a ceiling is to increase the mass of the ceiling, if you do not want to remove the ceilings, or you can’t, use a ceiling panel fixed below the existing ceiling to stop the sound from TVs and conversation. Use the NSSC2+ panel below your existing ceiling to block normal domestic sounds from transferring through your ceiling, simply screw through the existing ceiling into the joists, seal the edges with an acoustic sealant, plaster and decorate. These panels will reduce more noise than standard acoustic plasterboard due to the layer of rubber bonded in the middle which increases the mass of the boards and reduces vibration through the panels, this means less noise will pass through the panel into the room.
Increase the level of soundproofing of the NSSC2+ ceiling panels by installing them with soundbreaker bars.
Meet current Building Regulations for separating floors
A normal ceiling construction to comply with the current regulations would include the following materials.
- Acoustic insulation 100mm45kg/m³
- Soundbreaker bars
- 12.5mm acoustic plasterboard (two layers)
In order to comply with regulation Part E you will have to pass a sound test which will include an airborne test and an impact test, for more information on these levels, click here. This combination of materials should be combined with a suitable flooring solution laid onto the floors above, this is normally done with a floating floor, or an acoustic mat laid over the floor, this will help reduce impact noise coming through the floors.
An independent ceiling solution to reduce high levels of sound transfer
Independent ceilings are generally considered to offer the best levels of soundproofing when trying to reduce noise transfer, or to comply with Building Regulations. Installing an independent ceiling will drop the ceiling height by a minimum of 6 inches; if you can afford this sort of height loss you should consider the independent ceiling solution.
By installing a completely new ceiling with no connection to the existing ceiling means that sound can not easily transfer between the two structures, greatly reducing airborne and impact sound. New ceiling joists would normally have to be installed to carry out this type of ceiling solution, this should be carried out by a suitable trade’s person. For this type of construction you do not need to use the soundbreaker bars as the separation has already been created in the construction of the new ceiling.
Domestic ceiling soundproofing solutions
The most common methods for soundproofing an existing ceiling will involve either removing the existing ceiling or soundproofing below the ceiling. The solutions that we provide for domestic ceiling soundproofing can be used to suit the different requirements for each individual situation.
Each of these solutions is designed to suit the individual requirements of the rooms they are to be used and the type of sound you are trying to reduce. Ceiling System 1 requires the removal of the existing ceiling, the overall drop in ceiling height is around 80mm, and this system will offer excellent levels of noise reduction in most domestic situations. Ceiling System 2 is the most popular ceiling solution as it offers good levels of sound reduction, but it does not require a noticeable drop in ceiling, the existing ceilings have to be removed to use this system. Ceiling System 3 should only be used to reduce airborne sound transfer between ceilings, if you can not remove the existing ceiling, or use acoustic insulation system 3 can be installed below the existing ceiling, the drop in ceiling height would be around 33mm. For more information on these ceiling systems and other ceiling soundproofing products, click here.
Help and advice
If you would like any more help or require advice on products and installation please contact us, alternatively give us a call 08451 306269.
The Sound Solution based in York, North Yorkshire soundproofing and acoustic insulation supplies UK