How to Soundproof Brick Walls for Your Business
Working in a brick building has its perks. Brick is very dense, so outside sounds (the din from the street, construction or impact noise, and honking horns) have a hard time penetrating into your interior space.1
But that also means that sounds produced inside a brick space have a hard time escaping—if you’re tired of the constant echoing, you might be wondering how to soundproof a brick wall.
Before we explore how to soundproof brick walls, we’ll break down some sound science, help you set realistic expectations for your next “wall soundproofing” project, and posit some potential materials options depending on your overall sound reduction goals.
If you’re ready to conquer the echoes in your brick space, we’re here to help.
How Does Noise Travel Through Brick?
Brick is generally a good insulator against outside noise for two reasons:2
- It’s thick – Whether your building is made from solid bricks or hollow cinder blocks, the material protecting you from the outside is typically thicker than those separating wood-framed structures from the elements—plywood and drywall, specifically.
- It’s dense – Sound moves easily through porous, soft materials—brick is neither. The particles in bricks are tightly packed together, preventing the sound wave from efficiently traveling through those particles.
However, while sound doesn’t travel through brick very well, it does bounce off of brick. In larger spaces, this can create echoes.
This echoing issue may be keeping you from hearing speakers clearly in office meeting rooms, classrooms, or places of worship—even with the help of tools like microphones and amplifiers. In these spaces (where understanding the speaker clearly is critical), echo can be a critical concern.
Soundproofing vs. Sound Absorption: Setting Realistic Goals for Brick Spaces
When people talk about “soundproofing,” they’re usually trying to accomplish one or more of the following goals:
- Keeping outside noise from leaking into an inside space
- Keeping noises generated inside from leaking to the outside
- Dampening the noises generated inside of a space to clarify sounds or reduce echo
While the first two aims could be (at least partially) accomplished with soundproofing measures, the last goal is more closely tied to sound absorption. Let’s clarify both terms:
- Soundproofing is the process of blocking sound or reducing sound transmission.
- Sound absorbing or sound dampening suppresses the sounds inside of a room.
So, before you learn how to soundproof brick walls, you need to determine what you’re actually trying to accomplish. Still, we’ll discuss both soundproofing and sound absorption below.
Which Materials Work Best for Soundproofing Brick Walls?
The best soundproofing material for the job will depend on how you’re trying to reduce any airborne noise in your brick space—are you trying to keep sound from entering from (or escaping to) the outside of a room, or are you trying to muffle the sounds inside of a space? Let’s break down both options.
Sound Absorption Materials
If your office has a large, echoey, brick conference room, but outside sounds (like traffic noises) aren’t bothersome, you should consider sound absorption tactics first.
Brick doesn’t absorb sound well because it’s thick and dense—so to solve your echo problem, you’ll need materials that help prevent noise from continuously scattering about the space. People generally reduce echoes via one (or both) of the methods below:
- Increasing the acoustical surfaces in a room – Specialty sound-absorbing products are available, and they can effectively diffuse or trap the sounds echoing in a brick space. Some examples include acoustical panels, cementitious wood-fiber panels, and acoustical foams (but we’ll explore more options below).
- Investing in soft, fluffy furniture and accessories – Adding more throw pillows, couches, padded chairs, or thick cloth wall hangings to a space can make a dent in your echoes. These porous materials easily absorb the sounds bouncing around in your brick room, but they may not completely fix the problem.
Soundproofing Materials
If, instead of echoing, your brick walls aren’t keeping outside sounds out, you might need to focus on soundproofing rather than sound dampening.
Since brick offers relatively high sound insulation on its own, you might be able to attribute your sound leak to either:
- Cracks in the brick or mortar
- Sound infiltration through non-brick components, like:
- Windows
- Doors
- The seals around windows and doors
- Flooring transition pieces
- Electrical outlets
- The HVAC system
Depending on the source of the sound leak (and your desired level of wall soundproofing), you have a few options for materials:
- Soundproof drywall materials – Soundproof sheetrock is denser than traditional drywall sheets, and it can provide extra density against sounds from the outside. But you can’t just paste this sheetrock to your brick wall—you’ll have to frame out the existing wall with wood first.3
- Sounds vibration dampening compounds – Installing a dampening product and viscoelastic compound like green-glue compound between two layers of drywall can also help keep additional noise out. However, keep in mind that applying this material to brick walls won’t have the same effect.
- Soundproofing accessories – Using sound isolation clips or mass-loaded vinyl barriers (MLVBs) can help prevent sound transfer between walls in some applications. Sound isolation clips help block sound by decoupling the wall and vibrational transfer from the rest of the space while the vinyl barriers help block sound due to their material density.
We’ll discuss these and other soundproofing options in the next section.
How to Soundproof Brick Walls
If soundproofing walls—preventing noise from leaking into or out of a room from the outside—is your goal, you have a few options. They’re all relatively labor intensive, so before you prepare for a substantial DIY project, consult one of our acoustical experts for additional advice.
Option 1: Install Insulation
One way to decrease sound leakage into (or out of) your brick space is to install acoustic insulation and ensure everything is sealed around the brick using effective products like acoustical sealant.
The construction of your brick building will likely determine how you’ll install your insulation:
- If there’s a hollow space between the brick walls in your building, you may be able to remove one (or a few) bricks and blow a loose-fill insulation product into the space between each side of the interior wall.
- If your office is made primarily from brick but also features wood framing and drywall, you may be able to remove sheets of drywall to install a sheet-based product like cellulose insulation panels.
- If your building’s walls are only made from bare bricks, consider insulating the attic space to provide additional sound reduction.
Option 2: Install Drywall
You could also achieve additional soundproofing with drywall by using green glue coupled with drywall. If you’re prepared to install drywall, there are a few methods you could use to achieve additional sound insulation:
- Insulation and drywall – If you’re already considering adding drywall to a brick office space, why not insulate while the framing is still exposed? Adding an insulation product and drywall to an office space could significantly reduce unwanted noise leakage from the outside.
- Double drywall sheets – Using a combination of sound-blocking sheetrock and soundproofing compound (green glue), you could install two layers of drywall on each side of a brick wall to provide an extra layer of protection from sound infiltration.
Option 3: Create a “Room Inside a Room”
If having a soundproof room is critical to your business operations, consider creating one dedicated soundproof space in your office that harnesses the most powerful soundproofing material of them all—dead air.
To create a “room within a room,” you’ll need:
- Framing materials (plywood, 2x4s, and nails)
- An insulation product
- Drywall materials (sheetrock, joint compound, and screws)
- Floor soundproofing material
- A soundproof door
Using these materials, build a booth inside of an existing room—a space completely decoupled from the walls and floor of the room surrounding it. This is, essentially, how recording studios control noise.
How to Dampen Sound in Brick Buildings
While the options above can help mitigate sound leakage, they aren’t the most feasible solutions for reducing echos inside brick spaces. If you’re looking to dampen sounds, consider the tactics below.
Install a DIY Acoustical Panel or Other Sound Absorbing Media
If you’re interested in the DIY approach, you can make your own sound-dampening “acoustic panels” out of thick, fluffy blankets—moving blankets are one example. By hanging these on the walls or laying them on the floor, you can give bouncing sounds a place to “land,” preventing echoing.
Other DIY measures that could increase sound dampening include:
- Hanging thick sound absorbing curtains over windows
- Laying rugs on the floor
- Adding soft furnishings and accessories to your spaces, including:
- Fabric-padded office chairs
- Armchairs and sofas
- Throw pillows
Since the brick walls aren’t absorbing much of the airborne sound produced inside of your space, the “fluffy” materials above can help muffle some noise and reduce echoes.
Install Specialty Acoustical or Sound Dampening Materials
If you’d rather skip the DIY stage—or you’d like to supplement your DIY efforts with more sophisticated tools—consider installing specialty acoustical surfaces in your space. These are mostly panel-based, but the variety of colors and styles can complement the aesthetics of your space.
Some technologies available in today’s market include:
- Fabric-wrapped acoustical panels
- Wood wool panels made from cementitious wood fibers (these are paintable)
- Acoustical foam panels (which can also be hung from the ceiling in baffles)
- Bonded acoustical cotton panels (a budget-friendly solution)
- Stretch wall systems (which are highly customizable and simple to install)
- Polyester acoustical panels
Depending on the characteristics of your space, your noise-dampening goals, your aesthetic preferences, and your budget, you can use one of the solutions above or combine multiple tools to reduce the echoes in your brick office space.
Acoustical Surfaces: Controlling Noise for Over 35 Years
Learning how to soundproof a brick wall is simple, but choosing the right material and approach requires a close assessment of your goals, the sound characteristics in your space, and your budget.
When you’re looking for answers about soundproofing and noise reduction, Acoustical Surfaces can help. For over three decades, we’ve been the industry leader in acoustics, soundproofing, and noise and vibration control—our acoustical advisors can provide expert advice to help you achieve the results and high acoustic performance you’re looking for.
No job is too big or too small. Whether you’re learning how to deal with construction noise, abate traffic noise, diffuse echoes, or prevent sound leakage, reach out to our professionals today.
Sources:
- Masonry Association of Florida. What Is the STC Rating for Brick?. http://www.buildwithblock.com/knowledge-base/what-is-the-stc-rating-for-brick
- Hunker. How Soundproof Is Brick?. https://www.hunker.com/12618258/how-soundproof-is-brick
- SFGate. How to Hang Drywall on Block Walls. https://homeguides.sfgate.com/hang-drywall-block-walls-28999.html
