How To Soundproof A Room: DIY Tips & Cost Guide

By Jonathan

Find out how to soundproof a room by reading our comprehensive guide. We included DIY tips and the cost of hiring a contractor.

In today’s modern world more and more people are living in apartments with others living above, below and to the side of your living space. Your neighbour’s child might have just started saxophone lessons. Your upstairs neighbours are learning modern tap dancing and the person below has their television turned to full volume. You may even live near an airport or have buses changing gear outside your window every half hour, 24 hours a day. Apart from moving to the countryside, what can you do?

You can soundproof either your whole house….expensive! Or just soundproof a single room, somewhere to get away from it and unwind.

By the way, you have the law on your side too. In the USA, State laws have laid down Interior and Exterior Noise Codes which state the maximum air-borne and structure-borne sound allowable. As well as these minimum compulsory requirements, individual cities and towns have their own extra requirements. Check locally and see what these regulations cover. You may be able to reduce the exterior noise levels just be using the existing laws.

There are three ways to soundproof anything.

Block noise transmitted through the air by adding something thick and heavy to the structure. The extra mass will reflect sound or change the energy into heat.

Prevent sound from being transmitted through a structure by dampening impact noise.

Absorb the sound by preventing any noise that has found its way into the room from echoing, reflecting off hard surfaces and amplifying. Think about an indoor swimming pool and the amplified sound caused by the hard surfaces. Use lightweight and soft materials such as curtains, soft furnishings, indoor plants or the specialist sound absorbent materials available to buy. All these will reduce or prevent echo and amplification.

Pros and cons of soundproofing a room

Pros

Soundproofing provides peace and quiet from noise coming from outside as well as inside the house.
Gives privacy to the home-owner.
Allows normal household activities to go on without disturbing other members of the family.
Can offer privacy in buildings where confidential information is discussed, such as banks, medical surgeries, counsellors’ offices.
Allows musicians and film makers to work without extraneous noise interruptions.

Cons

Expensive to properly soundproof even a single room, although many makeshift partial solutions are available.
Installation can be inconvenient when retro-fitting.
Panels can be unsightly if they are installed openly.
Safety concerns. Electrical wiring and service pipes and ducts might be damaged on installation.
More difficult to get to existing cables and pipes for maintenance and repair work.
Prevents hearing essential sounds such as a child crying or a fire alarm.

Let’s soundproof a room

Ok. First thing is to see where the sound is coming in.

Walls?
Doors?
Ceiling?
Floor?
Windows?
Gaps in the existing surfaces?
Or all of these?

Sound is like water, it will always find an entry even through the smallest gap. If the noisy neighbours are above you, you can be sure that some of the sound is finding its way through the walls too. If you are going to soundproof the ceiling then you may as well soundproof the whole room.

The best sound insulation is something heavy and solid such as bricks and concrete. These aren’t easy to use when retrofitting a room, so what else can we use? There are plenty of specialist items available but we will be talking today about how to do it as simply and as cheaply as possible.

Do you remember what we said earlier about the three ways to soundproof?

Increase the mass and density of the structure.
Allow the structure to absorb sound energy.
Eliminate sound resonance and amplification.
We will be using these principles in different ways on each of your room’s surfaces.

Soundproofing a timber floor

Add at least 4 inches of acoustic grade mineral wool between the floor joists. This will reduce echo and sound amplification as well as absorbing sound energy.
Replace the floor boards and seal around the perimeter with acoustic sealant. Fill any knot holes as well.
Increase the floor’s mass by adding high mass and high density products. If you have wooden floorboards, lay MDF or high density chipboard on top. Use screws rather than nails to fix the boards in place. Screws will reduce movement and prevent the boards from moving when walked on. This will stop your floorboards from squeaking and creaking.
Lay acoustic flooring mat on top of the MDF. This is a sandwich of high density foam between two layers of dense rubber.
Use acoustic sealant to seal around the edge of the floor where it touches the wall. Remember that sound can find its way through the smallest hole.
Lay a good quality underlay followed by a thick pile carpet.
Remember to stagger the joints between the original flooring, the MDF and the acoustic flooring to make it as difficult as possible for stray sound to find its way through.

Soundproofing a solid wall (or a stud wall)

The best way to soundproof a room is to create a room within a room. This means creating a second wall within the first.

Seal all the perimeter gaps with acoustic sealant.
Build a timber stud frame with a gap of at least 10mm (0.5 inch).
Infill the stud frame with 50mm (2 inch) acoustic cotton or mineral wool.
Fit furring channels and drywall mounting clips onto the timber studs to hold the plasterboard in place. The mounting clips separate the timber stud from the furring channels by using dense rubber spacers.
Using self-tapping screws fit 15mm (0.5 inch) acoustic grade plasterboard to the furring channels.
Fit a 5mm (0.25 inch) Mass Loaded Vinyl mat.
Fit another layer of 15mm (0.5 inch) acoustic grade plasterboard.
Seal perimeter with acoustic sealant.
Skim plasterboard with ordinary plaster.
When you come to refit electric power sockets and light switches, remember to seal the joins with the wall using acoustic sealant.

By using different layers of different densities you have created a wall which will absorb and reflect different sound frequencies. This is better than simply using more of the same material.

Soundproofing a ceiling

The method of soundproofing a ceiling is similar to that of a wall except that there is more impact noise transmitted (footsteps) from upstairs.

Insert 100mm (4 inches) acoustic mineral wool between the ceiling joists.
Fit drywall mounting clips and furring channels across the ceiling joists.
Fit 15mm (0.5 inch) acoustic grade plasterboard to the furring channels.
Seal around the perimeter using acoustic sealant.
Fit layer of Mass Loaded Vinyl mat
Fit another layer of 15mm (0.5 inch) acoustic grade plasterboard.
Seal around perimeter with acoustic sealant.
Skim with plaster.
Seal around light fittings with acoustic sealant.

Doors & windows

Doors and windows are often the weak link when soundproofing a room. Acoustically rated doors and windows can cost hundreds or thousands of dollars, but it’s possible to do a lot with your existing doors. With doors we have three sound passages.

Sound penetrates their surfaces. If your door is hollow then it is easily penetrated by sound. If you can, replace the hollow door with a solid door. If you cannot do this then fit a piece of MDF about 12mm (0.5 inch) thick onto the door panel. Cut the MDF to size and put a layer of soundproofing ‘Green Glue’ between the panel and the door. Screw the MDF to the door sandwiching the sealant between the layers. Cut a piece of Mass Loaded Vinyl the same size as the door and fit this to the MDF.

The gaps between the door and the frame are a sound path. There are two gaps to fill here. The gap between the door frame and the wall, this is usually covered by architrave, and the gap between the door and the frame (jambs and header), covered by a doorstop. Remove the architrave moulding from the door frame exposing the gap beneath. Fill this with a dense closed cell sponge neoprene soundproofing rubber.

Use acoustic sealant to fill all the remaining gaps. Replace the architrave. Use a high quality silicone self-adhesive weather-strip to seal the gap between the doorstop and door. Cheaper versions will tend to deteriorate and crumble over time and the high quality types have special compression properties. Alternatively you can fit a door gasket which fits between the frame and the door edge. These have a neoprene seal and come as standard, adjustable or heavy duty.

The gap at the bottom of the door is the greatest sound path. This is the hardest gap to overcome as floors are very rarely level and the gap between door and floor will not be the same when closed compared to being open. An automatic door bottom can be mounted on the door panel, automatically rising when the door opens and dropping into place when the door closes.

Window glass is nearly useless when it comes to stopping sound from entering your room. You can buy special acoustic glass and have a double or triple layer of this in the window frame. Unfortunately it is very expensive so the easiest way around this is to build a soundproof plug to fit into the frame. You won’t have any light coming through but if you make it removable then you have the next best thing.

Soundproofing plugs are easy to make as follows.

Measure the height and width of your window and the depth of the window reveal or sill-board. This will give you the dimensions of your plug. If the window reveal is 4 inches then build a plug about 2 inches deep. This will give you a 2 inch dead air gap between the window pane and plug which will help with soundproofing. Do not press the plug against the window as sound will be conducted through.

Cut a piece of board the correct size to fit loosely into the window reveal. This could be fibreboard or some other lightweight board. MDF can be used but this is heavy and may be difficult to lift into place.

Cut two pieces of Mass Loaded Vinyl mat to the same dimensions as the board. Glue the mat to both faces of the board using contact adhesive.

Glue foam draught-strip to the edge of the plug, covering the cut edges of the board and the mat so it fits snugly into the opening. You can screw ‘D’ handles to the face nearest the room to provide a handhold.

Be aware that blocking up the window like this will prevent any solar heat build-up from diffusing into the room. It will probably be wise to limit this by first lining the glass with some aluminium foil to act as a reflector.

Hang heavy curtains over the plug and you can even fit shutters to the outside of the window for added benefits.

Deaden noise within the room

No matter how much you try to prevent unwanted noise from entering your room, there is always some that will find its way past the barriers you have constructed. This is where you furnish your room to prevent any echoes or amplification occurring.

Use soft furnishing within the room.
Lay carpets and rugs.
Fit heavy curtains.
Break up or cover hard surfaces such as cupboards and tables with soft padded surfaces.
Have potted plants with plenty of leaves.
If having hard surfaces is unavoidable, try not to have them opposite each other and parallel (avoid reflected noise).

You can also deaden the impact of unwanted outside sound by having machines that produce ‘white noise’ such as electric fans, air conditioning or de-humidifiers.

Soundproofing a room – Costs

The cost of soundproofing can range from a few dollars up to many thousands depending on the quality of the product, whether you are having the work done by a contractor or as a DIY project and what the purpose of the sound insulation is for. There are many soundproofing contractors available but this article is mainly about doing the job as a DIY project so we will concentrate on that. It must be remembered that these prices are indicative only and significant bargains can be found if you shop around. The manufacturers regularly release new improved products so it is worth keeping your eyes open for new technology.

Item	Cost
Door sweep 36”	$36
Door Jamb Seal (aluminium). Per foot	$6.50
Mass Loaded Vinyl. (0.5” thick) Closed cell. 48” wide x 30’	$435
Soundproofing Foam Mat (0.25” thick). 48” wide. Per foot	$11
Soundproofing Foam Mat (1” thick) 48” wide. Per foot	$20
Soundproofing Vinyl–Nitrile Tape (0.125” thick). 1” wide x 30’ long. Self-adhesive.	$8
Soundproofing Vinyl–Nitrile Tape (0.125” thick). 2” wide x 30’ long. Self-adhesive.	$15
Acoustic sealant. Per tube	$10
Sound proofing tape (0.125” thick) 0.5” x 25’ roll. Self-adhesive	$15
Drywall mounting clips. each	$5.50
Furring channels 6’ lengths	$3.50 to $6
Green Glue. 29 oz. tube	$17
Acoustic cotton fibre 3.5” thick. 24” x 94”. 8 pieces	$105
Energy efficient window foil. Per sq. ft.	$30
Soundproof Drywall acoustic grade plasterboard. 8’ x 4’ panel	$40

Are there any cheaper alternatives?

You may have noticed that the work involved in insulating your room against unwanted sound can be expensive and involve a lot of renovating existing walls and ceilings. This is all very well if you own the property, but what about if you rent and probably will be moving on in a couple of years?

The first thing you must do is decide what type of noise you intend to reduce. Is the noise airborne or impact noise, i.e. talking or footsteps?
How much do you want to spend on the job? Presumably as little as possible if you are in rented accommodation.

If thick carpets are out of your budget then choose a few good rugs and some thick curtains. There is no reason why you have to restrict the use of curtains to the windows either. Some thick colourful curtains, wall hangings or rugs can be hung on the wall to brighten the place up as well as reduce the noise.

Textured wall panels. These can be fixed directly onto the existing walls and will reduce the transmitted sound considerably.

Textured wall paint. This can provide almost as much soundproofing as the textured wall panel by reducing echoes and noise reflections.

Foam panels. These look like egg cartons. They prevent noise reflections and absorb sound as well.

Don’t forget to use white noise generators (we mentioned these earlier).

Why not use a contractor?

There are many specialist sound proofing contractors who will make your sound insulation project go smoothly. Most of the reputable companies will give you a free consultation where they will discuss with you your requirements and assess the best method of soundproofing. When you have chosen your contractor all that is required is for them to do the job. Some sound insulation material suppliers will also give you the free assessment, decide on the best system for your needs and provide you with fully illustrated fitting and instruction manuals for you to give your contractor.

Most sound insulation specialists are licensed general contractors who have seen an opening in the market locally that isn’t being exploited.

Because of the specialised knowledge required for this kind of work, they tend to be good all round tradesmen who are able to provide carpentry, plastering, electrical and plumbing work. Often there will be one tradesman supervising a group of labourers who work under his instructions.

Generally the cost to soundproof one average sized room without removing old insulation or modifying the existing structure will be as follows:

Item	Minimum	Maximum
Materials	$600	$1200
Labour	$500	$1300
Total job	$1100	$2500

While this will give you a good idea of the price you might be expected to pay when using a contractor to soundproof a room, the actual price spent will depend on many factors.

Quality of product
Experience of the contractor
Project accessibility
Time of year
Complexity of the project
Size of the project

Because of the variations it is imperative for the householder to make sure they receive a quotation in writing from the contractor before the work starts. The quotation must include the specifications of the materials used, any relevant local and State noise regulations and how the materials comply with these.

The cost of the materials will be measured by the foot, square foot, roll or sheet. Labour costs will usually be hourly or daily. Sometimes there may be a minimum labour rate.

Safety

If you do the job yourself,:

Ensure that you wear protective gloves and coveralls, eye protection and a dust mask. It isn’t only new fibreglass that produces damaging dust. If you are disturbing old walls and ceilings there may be surfaces infected by rodent droppings and old building materials contaminated by asbestos.

Take care that ladders are fixed securely and are in good condition.

When drilling into walls, floors and ceilings, keep away from water pipes, gas pipes or electricity cables.

Check with your home insurance company that any work will not compromise or invalidate your policy.

To finish

If you suffer from noisy neighbours, live near loud traffic, or have a teenage son who wants to learn the drums, it may be worth considering having either one room or your whole house soundproofed. It may not just be for your comfort, it might help your neighbours as well. There are many sound insulation products for sale that are suitable for someone with good DIY skills. If that isn’t your thing, then there are also many sound insulation contractors available to do the job for you. The success of the sound-proofing will depend on your requirements and how much you are willing to spend.

If you rent your property from a landlord, you won’t want to spend more than necessary. In this case there are plenty of low cost solutions to reduce the ambient noise.

Let us know what you think of the information provided in this article.