The second part of our guide to soundproofing at home covers floors. We’ve got lots of great tips that vary in cost and difficulty. You can also learn how to silence those pesky squeaky floors.
Soundproofing a floor doesn’t have to be as hard as you think, and it can make a huge difference to the quality of your life. In today’s post we give the lowdown on how you can do it for yourself.
These are tricks that can be done without hiring expensive professionals, but you might need some basic DIY skills. Using as many of these tips as possible would be most beneficial, but you can pick and choose what fits your situation and budget.
We start with our guide to soundproofing floors, which we’ve split into 6 steps. Following this there’s a dedicated section on fixing squeaky floors.
The main reason for installing a soundproof floor would be to reduce the noise of footsteps travelling through the floorboards. By soundproofing a floor you can also reduce the noise transfer caused by televisions, music, talking, furniture being dragged, and things being dropped.
The most effective way to do this is to make a specialist floor using some particular materials. However, doing this properly involves removing floor boards (not the joists). If this is something beyond what you had in mind then not all these tips will be for you. But, you’ll still definitely find something of value in this guide.
To make a soundproof floor you have to be prepared to lose some height in your room. You will be making the floor between one and two inches thicker.
Our soundproof floor combines some of the techniques we discussed earlier in part one of our guide to making a soundproof room. In fact, our new floor will be very similar to the “floating” wall described in this chapter.
This isn’t a complicated job but it takes a bit of sweat and muscle to remove the floorboards in the beginning. With a bit of planning it doesn’t have to take too long to finish either.
You can follow all 6 steps for the ultimate soundproof floor, or pick and choose certain steps to suit your budget or situation. Here’s a quick run through of what we’ll go over:
Step 1: Add an effective sound absorber
Step 2: Decouple the floor
Step 3: Identify & fix squeaky floor areas
Step 4: Absorb footsteps & add damping
Step 5: Absorb airborne noises
Step 6: Add a solid surface
Step 1: Add an effective sound absorber
The floor cavity (the empty space between the floor and ceiling) is one of the main culprits for transferring sound between levels of a building. As it is, it is probably mostly empty or air filled, and this is a problem.
Air offers very little resistance to sound energy, so if we can fill this space with something more substantial we can dramatically reduce the amount of noise that is transferred.
The first step is to remove the floor boards, and fill some of this empty cavity space with an effective absorber. The whole cavity does not need to be filled, but a decent layer must be formed between the joists. The more absorber we can lay, the better.
Important things to remember:
- It’s really important that we don’t compress the absorbing material. If it becomes compressed then it simply becomes easier for sound energy (vibrations) to travel between layers.
- We must not fill the air cavity to the top. By leaving a small air gap we make it harder for vibrations to be transferred through materials.
There are various materials that we can use to fill the air cavity. We can use cheaper materials like a dense polyester to do this, or a custom built acoustic treatment like mineral wool or Green Glue (see below).
Acoustical Mineral Wool
Mineral wool has excellent sound absorption properties. It is extremely dense which makes it perfect for reducing unwanted noise. It’s much more cost effective than things like acoustic batt too, which can be much more expensive but offer only a slight increase in performance.
This particular mineral wool comes in a pack of 6. It isn’t rigid and can be bent into shape for awkward spaces.
This versatile material can add an extra layer of sound insulation. It can be used in awkward places, and is a popular tool with builders seeking noise reduction. It’s really easy to apply and perfect for sealing those air gaps that noise loves to travel through.
Step 2: Decouple (or float) the floor (optional)
A further step to improve the soundproofing ability of your floor would be to add floor floaters between the joists and floorboards. Ideally, these floor floaters should be placed every 12 inches.These floaters reduce the amount of energy that can transfer between the boards and joists. This means less sound vibration will be transmitted, which means less noise. This stage gives the “floating” floor effect which many recording studios use to good effect. A further upgrade would be to replace your existing floor boards with OSB.
This technique is called decoupling. It’s a really effective soundproof flooring method.
Floor floaters are used to decouple floors. They reduce the contact points between surfaces, and therefore reduce sound transmission. They are inexpensive and an effective way of reducing sound transmitted through a floor. Lay them on top of floor joists at regular intervals of around 12 inches.
Step 3: Identify and fix squeaky areas of floor
Squeaky floors are usually caused by timber that is not held in place tightly enough. Wood can shrink and dry and shrink over time and air gaps arise. If you’re replacing the floorboards, make sure you take the time to walk around and put pressure on the boards in every location of the room. If you find a noisy area then simply use a few more nails or staples to fix it down more tightly. This problem must be identified and fixed at this stage, before the floorboards are covered.
For more ways to fix a squeaky floor, make sure you check out our guide on this problem further down the page. We’ve got solutions to fixing the problem from above or below the floor and even without removing the carpet or flooring. Soundproofing wooden floors doesn’t need to be as hard as you think.
Step 4: Absorb footsteps/add damping
An article titled ‘How to soundproof a floor’ wouldn’t be complete without some advice on how to combat noisy footsteps.
Footsteps are one of the main causes of noise coming through a floor and ceiling, so it’s important that we nullify them effectively. To do this we need to lay a layer of material which is soft enough to absorb the impact. It’s important that this material is not too dense, as this would aid the sound/energy transfer between rooms.
Therefore, the acoustic properties of this material are not as important. A reasonably dense polyester/urethane material of around an inch in thickness would do the job. This layer acts as damping to reduce vibrations between upstairs and downstairs.
There are specialist sound deadening mats that are built for this exact purpose. Two of the most popular soundproofing floor mats are Floor Muffler underlayment and Quiet Walk.
FloorMuffler and Quiet Walk Underlayments
These are both very similar in their purposes: to reduce foot fall noise and absorb moisture.
They are made from high quality materials that offer excellent sound insulation, but remain strong and flexible.Quiet Walk underlayment is very slightly cheaper, but Floor Muffler underlayment has a slightly better noise reduction rating.
They’re very easy to install and are both best suited to hardwood and laminate flooring. Floor Muffler is probably the best underlayment for laminate flooring. It’s the ideal sound deadening mat for a soundproof laminate flooring installation.
Step 5: Absorb airborne noise (voices/TV etc.)
We need to add one final layer to our new floor. This time the acoustic properties of the material are really important. We want something really dense and heavy which will absorb as much sound as possible. The ideal choices for this are SheetBlok and acoustic vinyl. They are super dense and designed to reduce sound transmission as effectively as possible.
It’s really important that we don’t leave any gaps in this layer. To seal the gaps we can use noiseproofing tape, or acoustic caulk (See step 6).
Mass Loaded Vinyl
Mass loaded vinyl is the perfect soundproofing material. It is heavy, dense and doesn’t take up much space. It comes in sizes of 40 square feet up to 100 square feet.
Great for sealing any air gaps, or offering an extra layer of sound insulation.
Step 6: Add a solid surface
Right now the floor is still very soft. We need to add a solid layer so that you can lay your flooring of choice on top. We need to choose a material that can be used without using any screws or nails. If we use nails or screw we will give the sound an easy route to travel through the floor. Something that uses a tongue and groove system would be perfect. Plywood or OSB would be good choices. We can seal the gaps at the walls with some acoustic caulk.
Acoustic caulk is liquid in form and can be used to seal any shape of gap. It is effective at sealing air gaps and plugging holes that sound would otherwise transfer very easily through.
Any kind of flooring can be attached to the last plywood layer. We can use nails to attach to the plywood, but we must not go any further.
Adding further layers would increase the worth of our acoustic floor even more. Just remember our acoustics basics, and don’t couple the surfaces (attach them with nails or without damping between them).
Using one of these stages would have a small benefit, but by using them together you will notice big results.
How to Fix a Squeaky Floor
Squeaky floors can be a serious pain, but it’s possible to get rid of the unwanted noise with some simple tricks.
Noisy floors are common to older buildings that use hardwood strip flooring, but pretty much any floor type is capable of causing this annoyance.
There are 2 main reasons for this:
1. As wood dries out over time, it naturally shrinks and leaves tiny spaces. This means when you apply pressure to wooden floorboards as you walk, you cause them to rub and squeak.
2. Nails used in flooring have a smooth, flat surface and don’t “grip” the wood like a screw does. Over time pressure causes the wood to move and cause squeaks.
It really depends on your home as to how easy this is to fix. Is your floor carpeted? Do you have access to the room below? We’ve got some answers for every situation so you can make floor noise a thing of the past. We’ve split the guide up into repairing from above and fixing from below.
1. How to Fix Squeaky Floors From Above
Not everyone has the luxury of viewing their floor installation from below. Fixing from above can be a little harder but it’s still very doable. The problem here is fixing the creaks and squeaks without damaging any nice carpet or flooring you might have.
A great way to do this is using a specialist kit from O’berry Enterprises. It’s well explained in the short video below. This kit is a top example of how to fix squeaky floors under carpet.
O’berry Floor Squeak Kit
This kit is designed to fix noisy floors from above with minimal damage to any carpets or flooring. It comes in carpet and hardwood versions, but can be used with the flooring/carpet removed too.
The kit uses special screws that have 2 different threads that grip the wooden joists firmly. Using the special tripod, the head of the screw is snapped off so that nothing is visible or felt above the floorboard.
This does leave a tiny hole in your carpet or flooring, but it might not even be visible. I guess it all depends just how much the floorboard noise is annoying you.
The kit is really simple to use and comes with full instructions for all they key steps, including locating the joists.
2. How to Fix Squeaky Floors From Below
Repairing squeaky floors from below is the easier way to do it. With access to the joists and subfloor you can pinpoint the places that are making the squeaks and target these areas for repairs.
The easiest way to do this is to have somebody walk around above you while you listen for the squeaks. Upon hearing a squeak, have your partner stop and tap on the floor, so that you are able to find the location from your position underneath the floor.
The next stage is to wedge a wooden shim between the subfloor and wooden joist. A shim is a small, thin, tapered piece of wood that is used to fill small gaps. To keep the shim in place, you’ll first want to cover it in some carpenter’s glue. The key is to be very gentle as you knock it into place. You simply want to fill any space, and make sure you don’t raise the floor. To hold it in place firmly, you could put a drywall screw through shim, joist, and subfloor.
Another way to remove the problematic space between the joists and subfloor is to use Squeak-Enders. These are screwed into the underside of the subfloor with a bracket reaching under the joist. By tightening a nut the Squeak-Ender works just like a vice and the joist is forced closer to the subfloor above. This serves exactly the same purpose as the shim solution.
If you find no gaps between the joists and subfloors or you find that the squeaks aren’t located over joists, then your problem might be between the floor and subfloor. In this situation you can use short screws to attach them more tightly. Just be careful not to use too long a screw or you’ll make a mess of your floor upstairs. This is how to fix a squeaky subfloor.
That concludes our guide to soundproof flooring in the home. We hope we’ve found this post of value and we’d love it if you’d share it with friends.
You can follow Home Recording Pro on Facebook (link on the right). We regularly post informative articles about music and sound, which we’re sure you’ll enjoy reading.
Don’t be a stranger as we have new posts going live very soon!