Using Insulation to Soundproof Existing Walls in a Home
As one of the top insulation contractors in Austin, we get asked all the time how to soundproof walls. Can you simply insert spray foam into the wall cavity? What about adding other types of insulation inside walls? Do I have to renovate to do the job correctly?
In order to answer some of those questions, we decided to put all the information below. This can help homeowners understand the issue and know what their options are to fix the problem.
This is a Brand New Home, Why Are My Walls Hollow?
See if this sounds familiar; you purchased property, hired a builder, waited several weeks while they built your home, and finally the move in day comes. You’re inspecting your new home with your family, excited, thinking about all the memories you’ll make there. Then someone goes to your new restroom. And you can hear every single sound from the next room.
How is that possible? Shouldn’t a new home have soundproofing insulation in the bathroom walls? Especially with how much it cost to build?
Unfortunately, this is very often the case with new homes in Austin, and all over the US. Texas, and the city of Austin, have very strict code requirements for insulating a home. Exterior walls need to be insulated to an R Value of 13. Interior walls however do not require any insulation at all. That means that every wall that’s inside the home can be (and often is) completely hollow, aside from pipes, wires, and wood framing. Builders aren’t required to put insulation in walls, and often don’t in order to increase their profit on their home.
So now when you’re sitting in the living room watching television, you can hear dad snoring in the next room plain as day. You’re thinking there’s no way you can endure this for twenty years. After multiple calls to the builders and sifting through your paperwork, you realize that it’s your problem now. What can you do?
What Are My Options for Soundproofing Existing Walls with Insulation?
Fortunately, with any issue you have with a home, there’s always a solution. HGTV may be a little overdramatized at times, but they do show you that almost anything is possible with a home renovation. But you’re not ready to do a complete demo on a new home. What about a simpler solution?
Here are all of your options along with pros and cons.
1. Spray Foam Insulation to Soundproof Walls
At least once a week we get a call asking if we can come over and just throw some spray foam insulation into a wall for someone. And it’s understandable that people would think that it would be possible, until you understand how spray foam insulation works.
Open cell spray foam does expand after it is installed, but not in the way that smoke fills an empty space. It’s sprayed on in the same way that you would paint a surface, in long smooth strokes. It adheres to the surface it’s sprayed on, then expands to fill small gaps.
In order to properly install spray foam insulation, the area needs to be fully open and accessable. This means either open framing or an open ceiling. There’s really no other way. If you tried to fill an empty wall cavity with spray foam, there’s no way you could even come close to distributing it evenly.
So, in order to use spray foam insulation to sound proof existing walls, you would have to completely remove all the drywall. Then cover every inch of space inside the framing. Let the spray foam expand. After that, you would have to install new sheetrock, finish, texture, and paint.
This is the only way it can be done correctly.
There is one other very important aspect to consider when deciding to use spray foam insulation to soundproof walls. It’s not as good of a sound barrier as other forms of insulation. While it does create a very good disrupter for noise, it’s simply not as good as other types of insulation.
- Excellent at sealing cracks and gaps
- Increases home value
- Must be sprayed on open surfaces
- Can be expensive
- Not the best sound barrier
2. Soundproofing Walls with Blown In Fiberglass Insulation
One of the most cost effective ways to install insulation between walls is to blow it it. This is done by using a stud finder to locate each cavity in the wall frame. Once this is done, an area is mapped out and a series of four inch holes are cut into the wall with a hole saw. Afterwards, loose fill fiberglass insulation, similar to what’s blown into attics, is blown into each cavity. This is done until each hole is packed full of loose fill.
While this seems like the easiest and most obvious solution, it’s not as simple as it sounds. The biggest obstacle is that not all framing cavities are completely open from floor to ceiling. There are often boards in the middle. Or there can be plumbing and wires that would cause another hole to have to be opened up below them. And these can’t be found with a stud finder, so you won’t know they’re there until you open up the top hole.
Then, after the insulation is blown into the wall, all those holes need to be repaired, finished, texture matched, and finally, painted. And with painting, in order for it to look perfect, the entire wall generally needs to be painted.
The last point to consider is that loose fill fiberglass insulation isn’t going to be the best sound barrier. With the top grade of Owens Corning loose fill fiberglass we can generally achieve a 50-75% noise reduction. For anyone who lives in a house with no insulation in the walls, this can be life changing. But it can end up being fairly costly for a less than perfect solution.
- Cost effective
- Do not need to remove entire walls
- Less waste going into landfill
- Generally takes the least amount of time
- Still requires wall repair, texture, and paint
- Could require dozens of holes
- Not the best sound barrier
3. Dense Packed Cellulose
Dense packed cellulose is a product that some contractors use to fill areas. It was once more common, but very few companies use this anymore. It is inserted into crevices as a wet substance to create a dense fill that reduces sound.
One of the reasons many people avoid this is that it is generally made up of recycled materials. One popular brand Green Fiber boasts up to 85% recycled materials. While this may seem great for the environment, the majority of that material is simply paper. Most people don’t want to use old newspaper to insulate their home.
Another issue is that it’s inserted into walls wet to create it’s density. This requires special equipment that is costly, which makes the procedure more expensive. It can be very messy. And many people are wary about pumping wet material inside the cavities of their home.
While you may still find some contractors that will offer dense cellulose as an option, very few will actively promote it.
- Can be used in existing walls
- Is a good noise barrier and insulator
- Has to be installed wet
- Is made of old paper
- Hard to find an installer
- Can be expensive
4. Soundproof Walls with Batt Fiberglass Insulation
Fiberglass is by far the most common form of insulation used in homes, and has been for some time. It’s used to insulate crawlspaces below floors, around the entire exterior, all the way up to the attic. It can be fiberglass batts or rolls which can easily fit inside framing. And loose fiberglass can be blown in attic floors to create an insulating blanket for temperature and noise.
The reason fiberglass insulation is so common is because of it’s versatility and cost effectiveness. It’s a terrific insulator for heat and cold. It’s often less expensive than other options. And fiberglass for soundproofing is one of the best solutions. It is often more than enough of a noise barrier for even the most lively family.
As great as this all sounds, if you don’t already have fiberglass batt insulation inside your walls, it’s not an easy task to get it there. Just as with spray foam, batt insulation has to be installed into open framing. This means that you would need to remove all existing sheetrock before installing it.
When we tell homeowners this is the option we recommend, the gasps are very noticeable. Especially with a brand new home, it can be hard to imagine ripping apart freshly installed sheetrock when the paint has barely had time to dry. But the fact is, this is what needs to happen if you want your walls to be soundproofed.
If you choose an experienced local company like South Austin Drywall you can rest assured that it will be done as cleanly, painlessly, and cost efficient as possible.
- Great for soundproofing
- Great for insulating against heat and cold
- Cost effective
- Very versatile
- Walls need to be removed for installation
5. Mineral Wool for Soundproofing
If you want the absolute best soundproofing insulation for walls, it’s going to be mineral wool. Mineral wool is typically not rated for it’s insulating qualities, meaning it has no R Value. It is however designed specifically for soundproofing. You wouldn’t use it on the exterior of your home, but to soundproof interior walls, mineral wool insulation is the top choice.
Mineral wool, like other types of insulation, does need to be installed in open framing cavities. It’s also very difficult to cut, so it’s recommended that you hire a professional installer.
There are a couple of companies that produce a type of mineral wool that is loose fill and can be blown in. But the cost of loose mineral wool insulation is extremely high. For overall cost and effectiveness, it’s a much better idea to just remove the drywall, install sound guard mineral wool product, then rehang the drywall. Anyone who’s going to invest the money in mineral wool is most likely looking for a perfect finished product.
- Excellent for soundproofing
- Excellent fire protection
- Walls need to be removed for installation
- Poor insulation against temperature
- More expensive than fiberglass insulation
6. QuietRock Sheetrock
The last item on our list has nothing to do with putting insulation inside your walls. This is a potential soundproofing solution that requires the least amount of demolition and debris. What if you could just add another layer of sheetrock to your wall and create a noise barrier that way?
Well, QuietRock is a company that offers that possibility. They create gypsum board that has it’s own soundproofing capabilities. It can be used instead of regular drywall, or applied on top of existing sheetrock. There are also several types of acoustical products and sealants that can be used underneath the QuietRock panels to increase their effectiveness.
Once installed, the QuietRock panels would still need to be floated and finished just like regular sheetrock. You would then need texture and paint as well. The main benefit though is that there is no demolition to the existing drywall meaning no mess and no garbage.
The effectiveness of QuietRock as a solution isn’t completely confirmed. Some people claim it works very well, others say it’s no better than adding another layer of regular drywall. It’s original design is to be used in conjunction with other acoustical products and soundproofing insulation. Generally, it’s used for people who want to create a music studio or home theater. But it can be used on it’s own and it will decrease the noise passing from one room to another. How much of a decrease is something that’s not easy to measure.
- Doesn’t require demolition
- Multiple products to improve effectiveness
- Not the absolute best sound barrier
- Still requires drywall finish, texture, and paint
- Sound reduction can vary
- Can still be an expensive solution
Which Soundproofing Option is Best for My Home?
Now that we’ve examined multiple ways to soundproof the walls in your home, how do you decide which is right for you?
Overall Cost
The first issue that’s on most homeowners’ minds is costs. Especially if you recently just purchased your home, you’re going to look at every problem or improvement to your home with dollar signs attached.
While some of these solutions are less expensive than others, there’s simply no cheap way to soundproof existing walls. Even hanging ugly acoustical panels or foam everywhere is going to be expensive.
So the first question you need to ask is whether soundproofing your walls is worth the investment for you. Some people may be able to live with being able to hear the toilet flush from the dining room. Others might find it impossible to work from the home office when they can hear the television.
One compromise that many homeowners find acceptable is only focusing on the most problematic areas. Instead of soundproofing every interior wall in the home, maybe just focus on bathrooms to start. Or mom’s home office. Whichever areas most need the attention can be addressed first, then worry about others at a later date.
How Long Will This Take?
Let’s face it, if you just moved into your new home a month ago, you probably don’t want a construction crew hanging around for a month. But maybe if you’ve lived there for a year, you don’t care what it takes to stop hearing every little noise in the next room.
Whichever soundproofing solution you choose, at least part of your home is going to be a work zone for a period of time. How long depends on a number of factors, but the main one is the actual extent of the project. If you call us and say you want us to remove the drywall and soundproof every single wall in your 4,000 square foot home with mineral wool, we’re going to get to know each other quite well over the next several weeks. But, if you only want blown in insulation between your living room wall and bedroom, we’ll be out of your hair in a couple of days.
Taking on a project like soundproofing walls is a commitment of some sort, no matter what. You need to take this into consideration when deciding how you wish to accomplish it.
This Could Get Messy
Almost every home renovation is going to create some mess, dust, and debris. Our drywall company employs some of the cleanest contractors there are, but this type of work gets messy. Cutting holes in drywall and blowing fiberglass insulation inside a wall is going to stir up all the dust that’s already settled there. Taking down all the sheetrock off of a wall and replacing it will create even more dirt.
When we work, we make it a point to mask everything, create walkways, and remove debris as it arises. Still, there absolutely will be particles of dust in the air and there may be a little dirt on the floor (which will be cleaned up shortly). The fact is, part of your home is going to be a work zone throughout the process.
Another thing to consider is whether you want a dumpster in front of your home for an extended period. If there’s any major demolition and sheetrock removal involved, all that material is going to have to go someplace. And your normal trash receptacle probably isn’t going to cut it.
How Badly Do Your Walls Need Soundproofing?
This could be the most important question in this entire article. How much noise is traveling between rooms? And how much of a disturbance is it?
If it’s a situation where you can sort of hear your daughter’s stereo occasionally, then blowing some insulation between a couple of walls would probably fix it.
But if your bathroom is right next to the area where you entertain guests and you can hear when someone tears the toilet paper, you might need fiberglass batt or mineral wool to soundproof the walls.
There’s also the possibility of doing some areas differently than others. Our company is very versatile with homeowners. We have no problems utilizing multiple different solutions to reduce the noise in different parts of your home.
Final Note on Noise Reduction in the Home
There is certainly a science to reducing noise in a home, whether it’s coming from the neighbors’ home or the next room. When you’re dealing with open cavities that separate rooms inside the home, anything is better than nothing. And as an insulation company, it upsets us greatly to see time an time again builders and house flippers neglect to put any insulation at all inside walls. For them, to insulate before adding sheetrock, the expense is minimal. But for a homeowner to have to do it afterwards, it is expensive, intrusive, and leaves them with the feeling of being taken advantage of.
Soundproofing existing walls is possible, but not painless. There’s no easy way to do it, which leaves many homeowners dealing with an issue for years that simply shouldn’t exist. If you are at the point of exploring options for noise reduction within the home, hopefully the information here helped. And if you’re in the Austin area and want to talk about how to get started on your project, South Austin Drywall has the expertise to guide you through the project the correct and most effective way for you particular situation.
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(512) 710-9144
