Open floor plans are all the rage in office configurations. Experts point to the increased levels of collaboration and relationship building that they encourage. From a purely financial standpoint, they also boast reduced construction costs.
There’s a downside to all of this openness, however. It’s noisy! Fortunately, there are steps you can take to keep that noise to a minimum, no matter what your office layout is.
Why Bother Soundproofing an Office Space?
When an environment is too loud, it can have a detrimental effect on productivity. According to one study, a noisy office space can inhibit productivity by 66%.
Not only does productivity suffer, but your staff can feel the effects as well. Too much noise can reduce employee satisfaction and harm their health. In Germany, a study found that prolonged exposure to 65 decibels (the equivalent of a classroom or open office floor plan) can increase someone’s heart rate to heart-attack levels.
Soundproofing won’t eliminate all the noise in an environment, but it can dampen it to healthier levels and prevent employees from complaining that they can’t hear themselves think.
Another, often overlooked, reason to soundproof an office space has to do with other people’s impressions. If you host clients or are trying to attract talent, people visiting your company should be greeted with a professional hum around the office, not a cacophonic symphony rivaling a playground.
Office Soundproofing Materials and Methods
Over the years, soundproofing solutions have evolved, and you have more choices than ever when it comes to reducing office noise. Here are some ideas to consider:
Acoustic panels: These absorb sound like a sponge in large spaces. Acoustic panels are great for open office plans where sound can bounce around and seem to magnify. They easily mount on a wall, just like a painting or they can be suspended from the ceiling. They can also be made to look like art and can be made in any shape, size or design configuration, so they’re often considered functional art.
Sound masking: This method adds sound to the environment, which serves to drown out other sounds around you. It’s a form of ambient noise delivered through a speaker system. The noise has the same frequency as human speech, and you can choose pink noise, white noise, and other types of frequencies. It’s kind of like camouflage for sound.
Soundproofing paint: This invention is relatively new however it’s an effective and affordable way to reduce sound from traveling between offices. Soundproofing paint, such as the product from SoundGuard is an easy and non-invasive solution for increasing the STC rating of a shared office wall.
Carpet and upholstery: Large open spaces tend to bounce and magnify sound. Upholstered items like furniture and carpet can absorb sound and keep an area quieter.
How to Soundproof an Office Space During a New Buildout
If you’re creating a new space, it’s helpful to look at not only the design and functionality but also the sound. We recommend that you start by evaluating your current needs and business model. Does your business rely on people being on the phone throughout most of the day? They may need separate offices. If you’re set on an open floor plan, consider adding other barriers to block sound travel.
Here are some other tips:
- Look for materials with a high NRC (noise reduction coefficient). This number ranges from 0 to 1, and has a rating that reflects the percentage of sound that the material absorbs. For example, an NRC rating of .8 means that it blocks 80% of the sound. Ideally, look for materials with an NRC between .5 and .9.
- Place electronics strategically. Anything that makes noise like a television, video conferencing system or phone should be placed in an area that won’t be distracting. For example, avoid putting these devices next to people who are on the phone a lot.
- Determine if you need window coverings. If there is a lot of street noise, install double pane windows. If you’re near the ground level or in a corridor that echoes sound, you may even need to add curtains as a sound dampener.
How to Soundproof an Existing Office Space
You may be able to swap out materials that allow too much noise to circulate with quieter options. For example, you could upgrade old doors, cubicles or wall dividers and replace them with materials with a higher STC rating.
STC is short for “Sound Transmission Class,” and it will provide you with a reference of how effectively materials such as interior partitions, ceilings, floors, doors, windows, and exterior wall configurations attenuate airborne sound. Each material has a different STC range, and the higher the number, the more noise it will block.
Here are some quick tips and fixes to employ:
- Add thicker carpeting
- Add soundproofing paint to both sides of shared walls
- Add couches and large plants to absorb noise
- Place partitions in open spaces to insulate noise to smaller areas
- Add a suspended ceiling with ceiling tiles that absorb noise
- Place acoustic panels on the wall
Soundproofing Commercial Walls
While soundproof paint is a fantastic place to start, it might not be enough to keep sound at bay. Other strategies to employ include packing the walls and ceilings with sound absorbing materials. Sometimes adding a second layer of drywall can help. Sometimes spraying additional insulation into the walls can help. The problem with both of these options is the hefty cost and added time to the commercial build out.
Examine your walls and look for any cracks and holes that will allow sound to enter. Make sure to plug them, mud them, caulk them or whatever else it takes to make sure they stop leaking sound transfer.
It’s very common in office buildings, even Class-A properties, for the walls to be non-demising which means the walls don’t go all the way up to the deck. If you see a suspended ceiling, also known as a drop ceiling, it means the walls are non-demising. This construction method is much cheaper to install than a finished ceiling however it creates more acoustic problems because those ceiling tiles are often very thin and not great at stopping sound and the sound that does get through them is very likely to travel over the non-demising walls and into nearby offices or conference rooms.
The two best ways to deal with these unfinished ceilings are to spray the ceiling tiles with a soundproofing paint or to hang layers of insulation over the non-demising walls. These two options together should help your office noise problems.
How to Choose the Best Soundproofing for an Office Space
As you evaluate these solutions, consider your unique situation. Ask yourself the following:
How noisy is my office? Do I need a complete sound overhaul or just a slight reduction in noise?
How large is my office? Larger spaces can create additional sound issues like echoes and magnification, so you may need to employ more advanced soundproofing mechanisms.
How much control do I have over the building? If you’re renting, you may need to have any tenant improvements cleared with the property manager. Or, you may be restricted by zoning or other municipal laws.
What is my budget? Some of these methods are significant investments, while others cost relatively little. If you’re on a budget, start with the less expensive solutions first and go from there.
A noisy room is one of the most common complaints among hotel guests. In fact, more people complain about this issue than they do about their room’s cleanliness.
To keep hotel guests happy, we recommend taking proactive measures to reduce the sound transmission from adjoining rooms, hallways, and outside. We’ll give you some tips on where to start and what materials to use, whether you’re looking for a quick fix or a complete property overhaul.
Hotel Soundproofing – The Importance of a Good Night’s Sleep
We all know that sleep is vital for health, and it’s arguably even more important for hotel guests. Take a moment to think about the guests staying at your hotel. Are they primarily vacation travelers? Are they families? Or are they there for business? Each of these groups is going to have different motivations for needing sleep, and they’re all equally important:
Vacationers: They want to rest and relax, especially after a long day of sightseeing. The last thing they want is to be kept up by a blaring television from next door.
Families: People traveling with little ones need a quiet place at night where their children can rest easy and not be jarred awake by loud noises.
Business travelers: Professionals traveling on business need a full night of quality rest to perform at their best. Considering that business travelers tend to be repeat guests, one negative experience can cost a hotel thousands.
Hotel Soundproofing Materials & Methods
Sound travels in waves, and soundproofing acts to provide a barrier that stops those waves from going into someone else’s room.
There are four ways to accomplish this effect:
Absorption: Adding insulating materials like fiberglass or mineral wool to absorb the sound and prevent it from passing through.
Damping: Soundwaves tend to create vibrations, but damping reduces or eliminates this by creating a barrier or “dead panel” that doesn’t vibrate.
Decoupling: This method separates the walls. Traditionally, the two layers of drywall would be connected as a single panel. With decoupling, the two pieces of drywall are separated, and a layer of insulation stays between them.
Mass: Using thicker and heavier materials also serves to block sound.
There are several types of materials to use in a soundproofing project:
Damping compound: This is a glue-like substance that isolates sound and vibration between two layers of material. It’s most often used in drywall applications.
Resilient sound clips: These clips are used in decoupling, and they serve to prevent sound vibrations from traveling.
Insulation: Depending on your preference and budget, you may choose fiberglass, mineral wool, cellulose or other materials.
Gaskets: Gasket tape, door gasketing, and a door bottom can all help to reduce noise coming in from outside, especially hallways.
As you select materials for your project, don’t forget to check the STC rating. STC is short for “Sound Transmission Class,” and it will provide you with a reference of how effectively materials such as interior partitions, ceilings, floors, doors, windows, and exterior wall configurations attenuate airborne sound.
Each material has a different STC range. For example, windows have ratings ranging from 18 to 38, while doors can range from 20 to 60. The lower the number, the less sound will be blocked, so when it comes to this measurement, the higher the number, the better.
How to Soundproof a Hotel Room During Renovation Periods
A property renovation is a perfect time to consider soundproofing. The benefit is that you get a newer, more modern look and feel and you’ll get an upgrade to your acoustics at the same time.
Here are some areas to consider in your soundproofing renovation:
Floors: If you’re replacing your flooring, consider adding soundproofing underlay on the hotel floor. A suspended ceiling in the lower levels can also reduce sound transfer.
Ceilings: In a multi-level structure, one guest’s ceiling is another guest’s floor. We suggest resilient sound clips or dual-layered drywall and a layer of Green Glue between the sections.
Doors: Hotel doors get a lot of wear and tear and tend to look dated. A new door style can enhance the look from both the hallway and inside the room. Look for a solid core heavy door, and ensure that you add a seal before installing the moldings. Also, adjust the hinges so that the door doesn’t slam shut.
Walls: You have a few options here. The first is adding layers of drywall. The second is to insulate between walls with something like mineral wool. If the hotel is undergoing major construction and it’s in your budget, you might consider doing both. However, if you do not want to demolish or alter existing shared walls, you should consider a non-invasive and easy to apply solution like soundproofing paint.
How to Soundproof a Hotel During Maintenance Periods
Identify where the noise is most likely to be coming from and focus soundproofing efforts there first. For example, if the exterior of the hotel is being repaired, make sure you’re equipped with windows that block sound, or, at the very least, thick curtains that serve as a dampener.
Ideally, you should keep the rooms adjacent to and adjoining the maintenance areas vacant. When that’s not possible due to property-wide maintenance or a fully-booked property, your last resort will be to dampen the sound near the source.
Soundproofing a Hotel
There are unique considerations when it comes to hotel space that might not apply to residential, especially considering the close proximity of guests to each other and the relatively smaller size of the rooms compared to an apartment or condo.
Here are some tips we recommend that will give your property an extra edge when it comes to soundproofing:
Doors: At a minimum, look for a door with an STC rating of 50. If you own or operate a luxury hotel, then your STC rating for your doors should be 60.
Windows: If your hotel faces a busy or noisy road, we suggest double pane windows with laminate glass.
Soundproof paint: This type of paint is ideal for hotels because it’s designed to muffle mid-range frequencies like voices. Sounds from conversations and the television frequently travel through hotel walls, so this paint provides an extra layer of protection.
Don’t wait for negative reviews to address noise issues. Instead, take a proactive approach to battle noise before the online reviews start showing up and it becomes a public relations nightmare. You don’t need to invest a ton of money to notice a difference. Adding SoundGuard’s acoustic coating and a fresh layer of paint is the fastest, easiest, and most cost-effective way to block an additional 8-12 dB of sound transmission between rooms.
Architects, developers, and contractors that build residential apartments, townhouses, single-family homes, and commercial office properties are largely concerned with keeping costs as low as possible without sacrificing quality.
Historically, the designers and builders have not given enough attention to the “soundproofing” of walls because there was a lack of cost-effective products and solutions. The reality is that walls are typically constructed as inexpensively as possible with shared walls being made from little more than 2×4 studs, a layer of drywall on each side, and some cheap fiberglass batt insulation.
When residents and tenants are surveyed on the perceived noise transmission from the walls detailed above, most individuals describe them as being “paper thin”.
Sound Transmission: A Frustrating Struggle
Your home is your castle and your bedroom is supposed to be a relaxing oasis. But what happens when that oasis is interrupted with the drumbeat of footsteps overhead, the nuisance of a TV blasting from your neighbor’s apartment, or the screaming of children that aren’t even yours?
From single family homes to apartment complexes, duplexes, hotels, and even offices…the reduction of noise transmission can transform a space into a more relaxing and more productive environment.
If noise is keeping you, or your tenants awake at night, read on to learn about the steps you can take to “soundproof” your home, apartment, hotel, condo or office space.
Why is Noise Such an Issue in Buildings and Homes?
Two words: Building Codes.
There are very few mandated construction requirements in the Uniform Building Code (UBC) or International Building Code (IBC) with regards to noise. Not to mention updates to the code happen only once every three years, with individual states lagging far behind that.
International Building Code 2006 states that separation between dwelling units and public and service areas must achieve STC 50 (STC 45 if field tested) for both airborne and structure-borne. However, not all jurisdictions use the IBC 2006 for their building or municipal code.
For example, in 2009, the majority of states were still using the 2003 version of the UBC/IBC. As of the 2003 version, those walls which are “shared” are required to have an STC rating of at least 33.
We won’t get into STC ratings (learn more here) but trust us when we say a rating of 33 does VERY LITTLE to block the transmission of sound.
Worse yet, this “minimum” STC rating is only applicable to “new” construction, meaning many homes, apartment complexes, hotels and other buildings constructed before that date are usually much worse off.
Understanding How Noise Travels
Don’t worry, we won’t get too technical here, but having a basic comprehension of how sound travels can provide you with some perspective on how to effectively reduce noise transmission through existing walls during your next remodel or renovation.
And now, a brief lesson on acoustics…
There are two basic types of sound: airborne and impact. That sound which is airborne travels, you guessed it, through the air. Impact noise are the vibrations transmitted through a structure, such as banging on a wall or the vibrations/impact from footsteps (often referred to as footfall noise).
Sound waves tend to travel along the path of least resistance, often making it difficult to accurately identify from where the sound is originating. For example, noises could be slipping through under a door, through HVAC ducts, or simply through poorly insulated walls.
Reducing Sound Transmission Through Walls
Walls rank among the top three structures commonly cited as sources of sound transmission. This is especially true when speaking about the adjoining walls between hotel rooms, apartments and condo units. These walls are often referred to as the party walls.
Let’s take a look at some strategies for reducing sound transmission through walls. We’ll divide these options into “construction” and “alternative no-construction” methods.
- Noise reducing drywall
Noise-reducing drywall (such as QuietRock) utilizes dual layers of gypsum that are separated by a viscoelastic polymer layer, all of which is designed to absorb sounds that would have otherwise transmitted from one room to the other.
- Layer Up
Not interested or able to tear apart the walls to replace them with noise reducing drywall? No problem. A fast, more affordable option is simply to add a single layer of standard ½” or ⅝” drywall right over the existing walls. This can effectively increase the STC rating of your walls by up to 6 points.
- Insulate Interior Walls
The right insulation can reduce vibrations that allow unwanted noise to pass through a wall assembly. Use insulation with higher STC and NRC ratings.
- Sound Dampening Tiles or Panels
Depending on the room and design, sound-dampening tiles may be an option. These tiles and panels are not generally made for aesthetics or suitable for living spaces but might make sense for commercial offices, coworking spaces and conference rooms.
The doors causing the most problems are typically found in hotels and multifamily living spaces but often times it’s not the door that’s the problem…it’s the air gaps around the door. To help resolve this problem, the proper door sweeps should be installed.
- Sound Isolating Clips
If you have access to the underlying studs of the wall, sound isolating clips can be used to help physically transmitted sounds from traveling through the studs to the drywall.
ALTERNATIVES TO CONSTRUCTION
Soundproofing walls without removing the drywall…
Construction and demolition is intrusive and costly, making the following alternatives a good option for any commercial property or homeowner seeking to reduce sound transmission through their walls.
- Soundproofing paint
Soundproofing paint such as that from SoundGuard is an innovative approach to sound reduction that is taking the industry by storm.
Why? Take a look at just a few of the benefits below:
- Easy, spray-on application
- Simple one-person process
- Consistency of performance with every coating
- Achieves a high degree of sound reduction
- Increases the STC rating
- Non-invasive (i.e. no construction)
- Mildew and mold resistant
As you can see from the above, soundproofing paint is a major hit with both commercial businesses and for residential applications.
- Sealing and Weather Stripping
Doors and windows can be a major source of sound transmission, but it’s not just the actual door or window that is the issue. Poorly insulated and sealed openings can be a major source of sound entering your rooms. Same goes for electrical outlets and vents/ducts. Weather stripping and acoustical caulk can be simple and cost-effective solutions to help.
Remember, if air can pass through or around it, so can sound.
- Soundproofing the Interior of the Rooms
If wall treatments or construction isn’t an option, there are still a few things you can do to help.
First up, soften the area. Sounds tend to bounce off of and through hard materials (especially those with broad flat surfaces like glass, tile, hardwood, etc). Consider adding carpet, soft furniture, and window accents like thick curtains.
How to Reduce Noise Between Rooms – Recap
Noise can be downright frustrating. But by following the tips in this guide you can be well on your way to establishing a quieter more peaceful and private space for you, your family or your tenants.
Recap of Options:
Noise reduction should be a consideration beginning with the planning, budgeting, design and construction process. When this isn’t an option (as with existing construction), steps can be taken to re-enforce the stability and insulation of the wall in order to reduce transmission of sounds. Though more invasive and costly, these methods are highly effective.
When construction is too expensive or not an option, soundproofing paint represents one of the best alternatives to explore. Products such as SoundGuard provide superior noise reduction and insulation at a fraction of the price of construction, and are fast, efficient, and user-friendly.
Ready to Take Back Control of Noise Today?
Let’s face the facts, lightweight construction, multi-unit housing, open floor plans and a whole host of other modern influences all contribute heavily to making living and office spaces noisier than ever before.
Whether soundproofing adjoining walls in a duplex or hotel, or soundproofing the interior walls of single family homes, noise reduction can dramatically improve the usability and serenity of the space.
Interested in learning more about sound transmission and soundproofing? Then you’ve come to the right place!
At SoundGuard soundproofing is what we do best. Our patent-pending eco-friendly soundproofing paint is taking the market by storm as a fast, affordable option to soundproof even the nosiest of rooms.
But enough about us. Let’s dig right in and help you learn more about STC ratings, how they are accurately calculated, and what they mean as it relates to your home or business.
What is an STC Rating?
STC, or rather “sound transmission class” for those of you that paid attention in school, represents an integer rating of how effective a partition (say a building wall) attenuates airborne sounds.
Widely considered a standard in the United States, since 1961, STC ratings have been applied to both residential and commercial construction alike as a way to measure the soundproofing ability of the following to reduce sound transmission between rooms:
In more lay terms, an STC rating provides you with information on how much (or little) a structure will stop or reduce the transmission of sound to the other side.
What is a Good STC Rating?
We’ve all been in a hotel room where the walls were paper thin and you could hear literally every little thing that went on in the room next door. That wall, no doubt, had a poor STC rating.
Because perception of sound is unique to each individual and up to interpretation, STC ratings need to be measured in order to calculate noise reduction capabilities on measurable facts, not individual opinions.
But what is considered a good STC rating?
STC ratings are measured using a uniquely designed scale where the higher the number is, the greater the ability of the measured structure or material to reduce sound transmission (i.e. better soundproofing qualities).
The scale utilized is sensitive, with even minor changes in ratings resulting in dramatic differences in sound transmission.
As to what STC rating is “good”, that is a definition that needs context. For example, what may be “good” for one business or room where soundproofing is vital, is going to be overkill for a room in which soundproofing isn’t needed nor necessary. Conversely, a “good” rating for a room where soundproofing isn’t important is going to be wholly insufficient for, say, a corporate boardroom where privacy and maximal reduction of sound transmission is critical.
How to Calculate STC Rating? – an overview
Stay with us here, we’ll try to make this as easy to understand as we can.
The first step when attempting to calculate an STC rating is to first measure the “transmission loss” on either side of the material or structure being measured. This measures the volume (dB) difference on each side respectively.
Next, the transmission loss values are tested individually against eighteen of the most common frequencies spanning a range between 125 Hz-4000Hz. These measurements are used to map out points on a graph that then form a curve. This curve can then be compared against standard STC reference curves.
Whichever curve your newly measured curve resembles the most represents the STC rating for your test.
As an example, if the curve representative of a wall you measured most closely resembles that of a standard STC 40 curve, then your wall will have an STC rating of 40.
As a friendly reference for calculation the following definitions apply:
- Frequency – represents the measurement of the tone or musical note of the sound
- Decibels – in lay terms, this simply measures how “loud” something is
- Transmission Loss – the measurement of the volume or decibel difference on either side of the structure being measured
How to Determine the STC Rating of a Wall
Ok, now that we’ve covered the basics of determining an STC rating, let’s dig a little deeper.
As it relates to multi-unit apartments (multifamily) or hotels, for example, we often get asked, “Can’t we just crank some music in one room and listen in the next room?”
That might seem like a decent way to determine the soundproofing, or lack thereof, but it’s not very scientific. If done correctly it might give you a perception of sound reduction but it’s always better to know the exact numbers.
So what’s a property owner or architect to do?
In order to properly ascertain the STC rating of a wall or other assembly, there are two approaches…
First up, if the original architectural drawings are accessible, it may be possible to look up the design assembly and postulate the intended STC rating by comparing that data to existing lab test data. While this is a good first step in estimating the STC rating, not all structures are assembled to spec. As such, our next test is much more accurate for a specific property.
Which brings us to the “Field Test”. Field tests, as you may have surmised from the name, are conducted on-site or “in the field”. Results of field testing provide us with what is called the ASTC or “Apparent Sound Transmission Class”. Testing in accordance with recognized standards is generally the best protocol to follow in order to make sure the testing is accurate, reliable and repeatable.
Testing in this way involves the use of an amplified speaker that produces broadband noise in one room (referred to as the “source”). The sound level produced by the “source” is then measured in both the source room and the “receiver” (adjacent room).
From that point, the reverberation time in the “receiver” affords the opportunity to calculate the respective sound absorption along with the corresponding source and receiver measurements. All of which results in the ASTC rating for the wall.
What is the STC Rating of Drywall?
When it comes to STC ratings, we get asked more times about drywall than most other materials. This is mostly because drywall is the universally employed material of choice for interior walls here in the United States.
However, answering the question isn’t as straightforward as you might first think.
Factors that will impact the STC rating of drywall include:
- Manufacturing process
- Raw material mixture used in production
- Auxiliary materials
- Thickness of the sheetrock
- And more…
That said, we’ll drop some average STC ratings for various applications below to give you a rough idea of what you may expect. Just know that there is bound to be variation.
A few examples:
- 5/8″ metal studs, 5/8″ drywall (2 layers total), No insulation = STC of 38-40
- 2×4 stud, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 34-39
- 5/8″ metal studs, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 43-44
With two sheets total, of 5/8” drywall utilizing standard insulation we often see STC ratings ranging between 30-34. With two total sheets of ½” drywall (common for residential interior walls) we usually see an STC rating of around 33.