Overview
Room-to-room noise reduction is rated in terms of sound transmission class (STC). The acoustical performance of common 16" OC wood stud walls is typically STC 30 to 34, and 24" OC wood stud walls is STC 36 to 39. This is considered poor, as conversation can be easily heard.
An old method to improve wall isolation since the 70's is a product called mass loaded vinyl. It is sold under a number a brand names, such as AcoustiBlok, SoundBarrier and others.
Acoustics and Vinyl
Noise can be attenuated with additional mass and many companies make vinyl sheets weighing about one pound per square foot. For this type of acoustical treatment, the mass of the materials is the dominant factor. However a wall already weighs 4 to 5 pounds per square foot before mass loaded vinyl is added, so the extra pound added by a single layer of vinyl is only a small amount of added mass.
Vinyl sellers display transmission loss data of bare sheets showing an STC of 26 or more. However presenting bare product performance is not related to the performance in an actual wall. The acoustic ratings of individual materials cannot be added to existing walls. For example, a single sheet of 5/8 inch thick gypsum board by itself has an STC of 28 --- 2 points higher than that of one pound vinyl. But you cannot add that 28 to a wall of 30 and get 58. In fact, an extra layer of gypsum adds only 2-3 STC points to any wall.
Adding mass to a wall follows mass-law which states that a doubling of wall mass adds about 5 to 6dB of isolation. That is, a doubling of mass of the entire structure!
When considering any product for soundproofing it is imperative to look for independent lab tests on full scale 8' x 12' walls performed to a current ASTM test method (ASTM E90 and E413). Remember individual STC values do not add up.
Sound Transmission in Walls
In a single stud assembly, the major path of sound transmission is directly through the studs rather than the air in the cavity. The addition of a vinyl layer does little to change this since the outer gypsum will be nailed or screwed directly through the vinyl into the stud. For significant improvements, one must change this path fundamentally, or introduce specific damping into the structure.
Actual Performance
There is one test from an independent lab showing a branded mass loaded vinyl at over STC50 on a 24OC wood stud wall. Unfortunately that test was conducted on a single wall section (4' x 8') rather than the required 8' x 12' wall, thus rendering the test invalid as it does not meet the requirements of ASTM E90. Three other full scale tests have now been published which show MLV on one side of a 24OC wood stud wall at STC 43 to STC 45. This is an improvement of about 15% less noise as heard by humans.
Cost Considerations
One pound per square foot vinyl sells for $1.50 to $2.00 per square foot at many online stores plus shipping (add about $1 per pound for UPS). So the delivered material cost averages $2.50 to $3.00 per square foot.
Vinyl installation is labor intensive. The vinyl needs to be unrolled, cut by hand around obstacles, attached with fasteners and carefully taped along every seam prior to the installation of the drywall layer. If one is not doing the work themselves, subcontractors charge $1.00 to $2.10 per square foot for installation.
Thus, in reasonable sized projects, one can expect an increase in wall costs of $3.50 to $5.10 per square foot. Consider a base of about $4.00/sqft if it is new construction for the studs, gypsum, and standard labor, and this results in a wall that averages $8/sqft. This will result in an STC 43 wall assembly with 24" OC studs.
Comparison
Soundproof drywall, such as QuietRock, creates a damped structure and thus behaves differently than MLV. Lab tests on soundproof drywall show STC's of 50 or better when used on one side of a 24OC wood stud wall. And this material replaces one side of drywall, saving money and time.
Low cost soundproof drywall today runs about $1.20/sqft (and is available at local dealers). Labor is about $0.60/sqft. Thus total wall costs can be under $5.30 per square foot depending on performance required. No special training or labor is required, since it installs just like drywall. The resulting performance is a 50% noise reduction (versus 15% for vinyl), the overall cost is 30% lower.
Resilient Channel is another technique which has been used since the 1960's. This requires hanging metal channels on the studs and then hanging drywall on the channels. The drywall must be isolated on all sides since touching the floor, walls or ceiling could acoustically "short out" the floating wall and reduce the performance.
If done right, with a double drywall on the RC side, and no shorts, it is reasonable to achieve an STC 48. The cost of this wall is under $6.00/sqft including labor. While the performance is less than soundproof drywall and the difficulty is higher, it is a mature method which was popular before the advent of soundproof drywall. So it may be worth still considering as an option.
Conclusion
Mass Loaded Vinyl has been sold for many years to help with sound isolation between rooms. They can provide limited increased STC values by adding additional mass and impedance changes to the wall. However, the effort, cost and detail required to use these materials needs to be compared to other more established and tested methods including soundproof drywall and resilient channels.
Saturday, June 21, 2008
Thursday, November 1, 2007
Luxury home builder delivers really Quiet homes
BUILDER LOVES QUIET
In 2003, Dale Garren, Vice President of Pinn Brothers Fine Home’s East Bay Division, searched for a soundproofing solution for their Palasage project, a 90 unit townhome prop¬erty in downtown Livermore, California. “We no longer wanted to use resilient channel in our walls. That system is so easily ruined that it just doesn’t make sense. In the field, if something can be compromised, it will be,” Garren explains. Due to the building’s design, they were locked into a single plate with stag¬gered stud construction. According to Garren, this configuration “makes it very tough to get to an STC 50.” Garren searched for a better solution and found QuietRock. Pinn Brothers used one layer of QuietRock acoustic drywall on both sides of the party walls. “When we did the field test, we achieved an STC’s in the 60’s and that shocked everyone, especially with a single plate, staggered stud wall.” More importantly, Garren says, “A high percentage of the homeowners, to this day, still comment on how quiet those units are. We were using resilient channel before QuietRock and everything we touched failed. We did not have this problem with QuietRock.”
"using resilient channel...everything failed...but not with QuietRock"
THE VALUE OF A QUIET HOME
Garren and the team at Pinn Brothers were so happy with the results of QuietRock at Palasage Townhomes that they were one of the first major builders to embrace Quiet Solution’s QuietHome program for their future projects. This program, in concert with the builders, helps provide a more comprehensive approach to acoustic design issues and the use of Quiet® products throughout a project to deliver a superior result. “We sell QuietHomes. The concept is simple and makes sense to buyers – and they value Quiet,” Garren explains. “This reflects well on Pinn and has been moving our properties faster.” Pinn Brothers is deploying the QuietHome program at two additional properties, currently in development: Tralee Townhomes and Silvera Ranch Villas, both in Dublin, California. For both projects, Pinn Brothers has installed one layer of QuietRock to each side of the walls, QuietHome high-STC Windows. At Tralee Townhomes, they are even installing a specially designed floor/ceiling assembly that uses QuietRock and QuietWood in order to substantially reduce the annoying “tap-tap” or high-heel footfall noise from above.
"The QuietHome Program has added a lot of value..."
Already confident about QuietRock, Garren had no worries about sound transmission through the walls. However, he had no previous experience using QuietHome Windows, and found himself pleasantly surprised. “In a multifamily environment they [QuietHome Windows] make a substantive difference. You can tell, they really are quieter.” During a recent visit to the Tralee site Garren describes, “I was amazed. The townhomes are right there on Dougherty Road and near the freeway. I walked into the model and opened the window and couldn’t believe a) how quiet it was with the window closed and b) how much noise is really out there. I was impressed. The difference was dramatic.” Garren was also new to the Quiet Solution floor/ceiling system. He remembers, “Before QuietHome floor/ceiling, we did the same thing people always did. We used lightweight concrete which is a nightmarish mess. Then we put resilient channel on the bottom of the joist, which similar to a wall system, is typically undermined.” Pinn avoided headaches with mold risk and scheduling risk, and got a better acoustic result. Garren adds, “With our current and future properties, we obviously want to have a quieter home. We prefer to exceed the basic code requirements. In addition, it’s a good feeling for homeowners, en masse, to say, ‘Wow, these are really quiet!’ At the end of the day, the QuietHome program, has added a lot of value.”
"it's hard to make a mistake with QuietRock...it is THE QUIET SOLUTION"
THE BENEFITS
Garren admits that using Quiet Solution soundproofing products is “Definitely cheaper than facing litigation” and that is a strong incentive. “Leaks and noise will get you in trouble in townhomes and the building industry as a whole. If the homeowner is listening to the conversations next door, that is not good. The cost is irrelevant. You want to pay to do it right with an outcome that is predictable—that is the value of using QuietRock, QuietWood and QuietHome Windows in our properties.” He continues, “The great news was that the total cost was lower using Quiet products than any other combination of materials and construction techniques would have been—plus it was simpler and more reliable too.” In fact, Garren doesn’t think twice about dealing with acoustics from the very beginning. Regarding the cost of remediation work if acoustics are not treated properly, Garren states, “I wouldn’t even want to contemplate it, I mean, the cost is staggering, I’d say 20 times more! It’s a situation I don’t want to be in, ever.” The product has saved Pinn Brothers a lot of money, because, as Garren says, “we are not getting sued. And the people that live there remark at how quiet it is... all of them.” Using the QuietHome suite of products has also helped Pinn Brothers take on the challenge of developing in what would’ve been more challenging locations. Knowing that the noise from railroads and freeways will not affect their residences, they are now building in areas not considered before. Garren adds, “Talk about green building - the best thing you could possibly have is a BART train running right by your building and not having to worry about the noise problems.”
“As homeowners have come to realize, quiet is an asset, in
addition to a code requirement. 12 times out of 10 you will exceed it with QuietRock. I am telling you, it’s hard to make a mistake with these products. As Pinn Brothers quickly did, more and more people will see the value in that. It is.
THE BENEFITS
Garren admits that using Quiet Solution soundproofing products is “Definitely cheaper than facing litigation” and that is a strong incentive. “Leaks and noise will get you in trouble in townhomes and the building industry as a whole. If the homeowner is listening to the conversations next door, that is not good. The cost is irrelevant. You want to pay to do it right with an outcome that is predictable—that is the value of using QuietRock, QuietWood and QuietHome Windows in our properties.” He continues, “The great news was that the total cost was lower using Quiet products than any other combination of materials and construction techniques would have been—plus it was simpler and more reliable too.” In fact, Garren doesn’t think twice about dealing with acoustics from the very beginning. Regarding the cost of remediation work if acoustics are not treated properly, Garren states, “I wouldn’t even want to contemplate it, I mean, the cost is staggering, I’d say 20 times more! It’s a situation I don’t want to be in, ever.” The product has saved Pinn Brothers a lot of money, because, as Garren says, “we are not getting sued. And the people that live there remark at how quiet it is... all of them.” Using the QuietHome suite of products has also helped Pinn Brothers take on the challenge of developing in what would’ve been more challenging locations. Knowing that the noise from railroads and freeways will not affect their residences, they are now building in areas not considered before. Garren adds, “Talk about green building - the best thing you could possibly have is a BART train running right by your building and not having to worry about the noise problems.”
“As homeowners have come to realize, quiet is an asset, in
addition to a code requirement. 12 times out of 10 you will exceed it with QuietRock. I am telling you, it’s hard to make a mistake with these products. As Pinn Brothers quickly did, more and more people will see the value in that. It is.
For more information on products see http://www.quietsolution.com
Tuesday, September 25, 2007
Addressing Climate Change Requires Quiet
As the world awakens to the emergency of climate change, we must begin to look at every facet of life to see things that are right in front of us, but non-obvious. CO2 and other greenhouse gases have clearly and undeniably changed our climate forever. A rise in temperatures and sea level are guaranteed at this point. The question is not if, but when.
Americans in particular have enjoyed sprawling communities far from the workplace for the better part of 50 years. We have become used to large houses on quiet streets, far from the action and noise of the city. And we have become used to longer commutes, 25% longer than a few decades ago with some over 60 minutes in each direction. Wasting the little time we have and belching CO2 the whole way there…and back.
Recently, there has been a move back to cities, in high quality multifamily and mixed use communities, especially by the younger generation. They enjoy the activities, proximity to entertainment, and easy maintenance this style of living bring. And it turns out that this alone could reduce CO2 by 30% or more, very rapidly. High quality multifamily projects in urban environments help in several dramatic ways. To start, most people who live there also work close by. They take public transportation daily or walk or ride a bike. Taking millions of cars off the road every day.
The dwellings are beautiful and upscale but significantly smaller than a single free standing house. They are built tighter, with more insulation, and the heating can be very efficient with most heat loss occurring into an adjacent unit (this sharing some energy). The CO2 generated due to the heating and cooling of condo’s can be 70% less than a single family home.
The amount of lawn to water is close to zero (saving CO2 from pumping the water to the home and also saving precious clean water). And the amount of materials used to build a condo versus a single family home can be 30% to 50% less, saving in CO2 from manufacturing these items (a major source of CO2 actually) as well as the transportation to the jobsite and installation time and energy.
Without questions, one of the best moves a person can make to have a major impact on the environment is to purchase a condo or townhome in an urban setting. If everyone in the US lived in this way, we could cut carbon emissions by 1B metric tons or more. That is about what Italy and the UK generate as a whole combined.
But today, the number one complaint of occupants is noise. And it is this noise that keeps people from moving into urban environments, and thus continuing to generate more CO2. Noise from the street, noise from neighbors, noise when you are trying to sleep.
According to a 2007 report by the World Health Organization, excessive noise in everyday life is not only responsible for unhappiness, poor learning, poor concentration, stress, poor sleep and overall crankiness…but it is also responsible for deaths. Yes, you read it correctly, deaths. How many deaths? According to the report, 3% of heart attack deaths can be attributed to noise in everyday life. The stress and sleep deprivation caused by everyday noise in urban environments is responsible for tens of thousands of premature deaths annually. That is a wake up call.
What to do? Well, new technology now exists to deal with both street noise as well as neighbor (party wall) noise. Easily and cost effectively.
Street noise is being addressed by newer high STC windows and doors. Sound Transmission Class (STC) is a way to measure how much noise gets through. High quality dual-pane windows from most every major manufacturer typically have an STC rating of only 27 to 29. Fine for a quiet street, but not interesting for an urban setting. High STC windows from several manufacturers now exist which raises STC values to 38 to 42 or more. That is 50% to 60% less noise. Of course, if you don’t ask your builder for these you may not get them. They can cost 3X what low cost windows do. But it is worth it. You will sleep better and be less agitated everyday. And what is that worth? A few dollars a month on the mortgage…probably.
Party walls can be handled properly or poorly…and often it is poorly (unfortunately). Old techniques such as resilient channels often perform poorly or fail in time. Due to the advent of home theaters, party walls should be STC 60 to 65 or even higher. But the law, written decades ago, requires only STC 50 walls (or STC 45 after installation), which is barely enough to isolate simple conversation and not much else.
It used to be difficult to achieve wall STC’s of 65 or more, but that changed with the introduction of soundproof drywall (such as QuietRock) in 2003. This is a newer category of products that actually saves builders money and provides significantly improved STC values. STC 50, 60, 70 and even 80 walls have been built and tested for several years now using these products. And while the drywall itself is more expensive than standard drywall, it is overall cheaper to the builder to hit a given STC value than older methods (including time and labor) and is much more reliable. So you can save money and never hear your neighbor again.
Floor/ceiling systems can suffer from similar issues in units with neighbors above or below. And again, new technologies exist to deal with these including the use of soundproof drywall on the ceilings and damped subfloors above plus advanced flooring isolation.
What this leads us to is the important and undeniable connection between quiet living environments and climate change. According to a survey completed by the National Research Council in Canada in 2001, there is a direct tie between people wanting to stay and the STC values of party walls. As STC approached 60, some 75% of respondents were happy with their environment and wished to stay. As STC dropped to 40, a full 45% wanted to move out. And noise was the big complaint at that level. And if people are unhappy living in their condo, they will leave and tell others to stay away.
If we are to impact climate change through urbanization (and we must), we must also deal with the noise issue head on. This isn’t about saving a few dollars or doing it the old way because that is good enough to meet code. Instead, it is about significantly impacting CO2 while encouraging people to move into and enjoy quality urban settings. And they will only do that if builders address their number one complaint…noise. It is time all builders take responsibility and build-in high STC windows, doors and walls. And buyers take responsibility and ask for this as an amenity (or ask about STC ratings) before you buy. This may inspire builders to do what is right because you are asking for it. Otherwise, you’ll be in that 45% that want to move back out, and do more harm to environment…all due to a noise problem easily solvable today.
Save the planet…buy a (really) quiet condo.
More information on QuietRock and Quiet Windows can be found at www.quietsolution.com
Americans in particular have enjoyed sprawling communities far from the workplace for the better part of 50 years. We have become used to large houses on quiet streets, far from the action and noise of the city. And we have become used to longer commutes, 25% longer than a few decades ago with some over 60 minutes in each direction. Wasting the little time we have and belching CO2 the whole way there…and back.
Recently, there has been a move back to cities, in high quality multifamily and mixed use communities, especially by the younger generation. They enjoy the activities, proximity to entertainment, and easy maintenance this style of living bring. And it turns out that this alone could reduce CO2 by 30% or more, very rapidly. High quality multifamily projects in urban environments help in several dramatic ways. To start, most people who live there also work close by. They take public transportation daily or walk or ride a bike. Taking millions of cars off the road every day.
The dwellings are beautiful and upscale but significantly smaller than a single free standing house. They are built tighter, with more insulation, and the heating can be very efficient with most heat loss occurring into an adjacent unit (this sharing some energy). The CO2 generated due to the heating and cooling of condo’s can be 70% less than a single family home.
The amount of lawn to water is close to zero (saving CO2 from pumping the water to the home and also saving precious clean water). And the amount of materials used to build a condo versus a single family home can be 30% to 50% less, saving in CO2 from manufacturing these items (a major source of CO2 actually) as well as the transportation to the jobsite and installation time and energy.
Without questions, one of the best moves a person can make to have a major impact on the environment is to purchase a condo or townhome in an urban setting. If everyone in the US lived in this way, we could cut carbon emissions by 1B metric tons or more. That is about what Italy and the UK generate as a whole combined.
But today, the number one complaint of occupants is noise. And it is this noise that keeps people from moving into urban environments, and thus continuing to generate more CO2. Noise from the street, noise from neighbors, noise when you are trying to sleep.
According to a 2007 report by the World Health Organization, excessive noise in everyday life is not only responsible for unhappiness, poor learning, poor concentration, stress, poor sleep and overall crankiness…but it is also responsible for deaths. Yes, you read it correctly, deaths. How many deaths? According to the report, 3% of heart attack deaths can be attributed to noise in everyday life. The stress and sleep deprivation caused by everyday noise in urban environments is responsible for tens of thousands of premature deaths annually. That is a wake up call.
What to do? Well, new technology now exists to deal with both street noise as well as neighbor (party wall) noise. Easily and cost effectively.
Street noise is being addressed by newer high STC windows and doors. Sound Transmission Class (STC) is a way to measure how much noise gets through. High quality dual-pane windows from most every major manufacturer typically have an STC rating of only 27 to 29. Fine for a quiet street, but not interesting for an urban setting. High STC windows from several manufacturers now exist which raises STC values to 38 to 42 or more. That is 50% to 60% less noise. Of course, if you don’t ask your builder for these you may not get them. They can cost 3X what low cost windows do. But it is worth it. You will sleep better and be less agitated everyday. And what is that worth? A few dollars a month on the mortgage…probably.
Party walls can be handled properly or poorly…and often it is poorly (unfortunately). Old techniques such as resilient channels often perform poorly or fail in time. Due to the advent of home theaters, party walls should be STC 60 to 65 or even higher. But the law, written decades ago, requires only STC 50 walls (or STC 45 after installation), which is barely enough to isolate simple conversation and not much else.
It used to be difficult to achieve wall STC’s of 65 or more, but that changed with the introduction of soundproof drywall (such as QuietRock) in 2003. This is a newer category of products that actually saves builders money and provides significantly improved STC values. STC 50, 60, 70 and even 80 walls have been built and tested for several years now using these products. And while the drywall itself is more expensive than standard drywall, it is overall cheaper to the builder to hit a given STC value than older methods (including time and labor) and is much more reliable. So you can save money and never hear your neighbor again.
Floor/ceiling systems can suffer from similar issues in units with neighbors above or below. And again, new technologies exist to deal with these including the use of soundproof drywall on the ceilings and damped subfloors above plus advanced flooring isolation.
What this leads us to is the important and undeniable connection between quiet living environments and climate change. According to a survey completed by the National Research Council in Canada in 2001, there is a direct tie between people wanting to stay and the STC values of party walls. As STC approached 60, some 75% of respondents were happy with their environment and wished to stay. As STC dropped to 40, a full 45% wanted to move out. And noise was the big complaint at that level. And if people are unhappy living in their condo, they will leave and tell others to stay away.
If we are to impact climate change through urbanization (and we must), we must also deal with the noise issue head on. This isn’t about saving a few dollars or doing it the old way because that is good enough to meet code. Instead, it is about significantly impacting CO2 while encouraging people to move into and enjoy quality urban settings. And they will only do that if builders address their number one complaint…noise. It is time all builders take responsibility and build-in high STC windows, doors and walls. And buyers take responsibility and ask for this as an amenity (or ask about STC ratings) before you buy. This may inspire builders to do what is right because you are asking for it. Otherwise, you’ll be in that 45% that want to move back out, and do more harm to environment…all due to a noise problem easily solvable today.
Save the planet…buy a (really) quiet condo.
More information on QuietRock and Quiet Windows can be found at www.quietsolution.com
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