Sunday, January 8, 2023

SOUNDPROOFING A CEILING

Soundproofing a ceiling can be key to your enjoyment of spending time in your home. And it’s not something that only applies to those living in flats, either — if you live in a terraced or semi-detached house you might also find yourself plagued by noisy neighbours or lodgers. Even those living in detached homes may have to endure noise transfer from upstairs (teenagers playing loud music or children running around, for example).



Here’s all you need to know about soundproofing a ceiling, no matter what types of ceiling or home you have.


Before you can find the right soundproofing and noise control solution for you, think about:


● The type of noise you are trying to stop

● The type of ceiling you have

● Whether the noise is coming from above or below

● How loud the noise is.


Once you’ve answered these, you’ll be better placed to understand the options available and how they can solve the issue. And for soundproofing to work well, the right systems must be selected and it’s crucial they are fitted correctly. Ian Baker from The Soundproofing Store agrees: “Soundproofing is just like waterproofing — it’s only as good as its weakest point. Think of a car window. Even if it’s open just a tiny bit, you get all the noise from outside coming in.”


DIFFERENT KINDS OF NOISE


Firstly, it’s important to ascertain the kind of sound you are faced


with. “There are two types of sound that need to be dealt with when it comes to soundproofing a ceiling: airborne and impact,” explains Ian Baker.


“Airborne is the type of noise created by talking and sound of the television, for example. Impact noise, on the other hand, is caused by footfall, such as people running or walking around or items being dropped.”


The soundproofing measures required to stop the transfer of these different types of noise are not the same.


“To prevent airborne sounds you need to add extra mass to the ceiling, while to reduce impact noise you need a dampening system to absorb the vibrations,” explains Ian.


“The higher the decibel (dB) figure for airborne noise, the better, while the lower dB figure for impact noise the better. It’s usually necessary to address both airborne and impact noises.


TYPES OF CEILING


Your next consideration should be the type of ceiling you have: timber joist or concrete. “Concrete ceilings tend to have a high level of mass and density, which should already reduce a good level of airborne sound,” begins Mike Cunningham from Noisestop Systems. “With concrete ceilings, impact sounds will transmit through this material. Timber ceilings that have not been soundproofed often have both impact and airborne sound transfer between floors.”


Although the solutions for each type of ceiling are different, in general, there are three main aspects to soundproofing: adding mass, incorporating a material to absorb sounds, and creating separation.


● Mass: The higher the mass, the more you will reduce airborne sound. High-mass products such as acoustic insulation, soundproof plasterboard and mass-loaded vinyl will significantly reduce airborne sound.

● Absorption: This refers to the ability of the ceiling to absorb sound. Acoustic insulation between ceiling joists will help absorb sound as it transfers between floors. Empty ceiling cavities will often act as a drum, and the sound will resonate inside the cavity and amplify the sound.

● Isolation/separation: Creating isolation within the structure of the ceiling will reduce vibration. As the impact and airborne sounds transmit through solid surfaces via the vibration, it is essential to isolate the existing ceiling from the new soundproof ceiling.


TIMBER CEILINGS


In general, the approach to soundproofing a timber ceiling involves a combination of insulation, metal rubberised clips to absorb vibrations, metal channels or battens, and perhaps vinyl or rubber panels and a couple of layers of acoustic grade plasterboard. “The majority of our clients have timber joist ceilings,” says Ian Baker. “When we soundproof timber ceilings we need to create a sealed chamber which will absorb vibrations.


“First we add acoustic mineral wool insulation. Once the insulation is in place, metal rubberised clips are attached to the bottom of the joists, before ‘furring bars’ or ‘furring channels’ (metal battens) are fixed to them to take the new plasterboard.


“Next you need to add mass to deal with the airborne noise. We use two layers of acousticgrade plasterboard, using a rubber sheeting, called TecSound, between them. The aim is to use a combination of several high-mass materials for the best results — rather than lots of the same layers. Using this kind of system, you can expect to lose around 60mm of ceiling height, but you should get a 75% reduction in noise.”


CONCRETE CEILINGS


Here a different approach is required. “Because concrete ceilings already have high levels of mass, it is customary to treat these ceilings for impact sounds from above,” says Mike Cunningham.


“However, if you have plenty of height in the room, you could consider installing an independent ceiling. This type of ceiling does not touch the original and requires new ceiling joists. It does not require too many specialist products as the ceiling being independent is the key element.”


However, the most common method of soundproofing a concrete ceiling without losing head height is to use a system of products fixed directly to the concrete ceiling. “In an ideal  world, a new suspended frame would be built below the concrete ceiling to decouple it from the original structure,” says Ian Baker. “Our standard specification is to use our ReductoClip system directly to the concrete ceiling, resulting in only a 60mm loss of space. Mineral wool is also added in between the first layer of plasterboard and the original concrete ceiling, to stop any sound from amplifying within this space.”


When soundproofing a concrete ceiling to block out noisy neighbours, the sound can also travel down the walls so it is worth doing an ear test, listening for any noise coming through the walls. If this is the case, then soundproofing the wall will also be required.


THE CEILING LIGHT EFFECT


So does having ceiling lights affect soundproofing? “Think of sound like water in a bath — if you pull the plug out, all the water escapes,” explains Mike Cunningham. “Sound works in a similar way; if you leave even a small hole or gap, it will compromise the level of soundproofing.”


For this reason, you want to avoid cutting any holes in your ceiling to take new lights. Surfacemounted spotlights or pendants are a better option where sound travel is an issue.


THE COST FACTOR


This will largely depend on the size and type of your existing ceiling, and your approach. Based on a ceiling size of 4m x 4m, using a product such as the ReductoClip ceiling system, materials would cost around $1,800 - $2,000,


Another factor is whether you choose to do the work yourself. Many soundproofing kits can be fitted by a competent DIYer — but some of the elements are very heavy and so this is a job for two people.


Alternatively, you’ll find most soundproofing specialists will have a list of trusted installers.