Sound vibrations are transmitted through the air, causing problems with noise entering and exiting your home studio. Many materials used in home construction, such as wood and drywall, are conductors of sound. Blocking out these sound waves is the purpose of a soundproof room. This is usually done for a home music studio.
For the highest quality, most complete soundproofing, you should hire a professional. The cost of a professional can be prohibitive for many people. You can construct a soundproof room in your home with a little knowledge and the right soundproofing material.
How Soundproofing Material Works
Soundproofing material works by interrupting sound vibrations. This isolation must be complete, or you are wasting your time. One hole in the material will ruin the effect. Sound waves can travel through the smallest hole or gap in the material.
Fiberglass is the material preferred by many professionals. Lead barriers are often used in professional studios. These need to be installed by someone knowledgeable in both the material and the principles of sound waves. This understanding makes the professional the best choice if you want the job done as thoroughly as possible.
Sound Absorbing Techniques
Sound absorbing and soundproofing materials work differently. Each product has different purposes and the two are not interchangeable.
Acoustical foam is sometimes used by professionals and often used by the do it yourself person. This is not used for soundproofing, but for absorbing the sounds within the studio. Not all foam is created equal and these materials are rated for fire safety. The ratings are listed as class A, B, or C. Fatal fires have resulted from use of inferior materials. The class A material is the most expensive, but is the most fireproof. Your safety is worth the additional expense. When using foam, make sure there is a clear path out of the room in the event of a fire. Fire resistant materials release toxic fumes in a fire, which will kill you faster than the flames.
The purpose of soundproofing material is to reduce the sound waves being transmitted into your studio from the outside. This is generally done through material in the walls, ceiling, floors and windows of the studio. Most materials are rated for the number of decibels the sound is reduced. For the materials to be effective, they must be installed correctly without holes or gaps.
Using and Installing Soundproofing Materials
A double wall is the ideal sound barrier that can be built by the do it yourself handyman. When building a second wall, it’s important to use floor insulation. This prevents the sound waves from being transmitted between the two walls via the flooring. Flooring carries acoustical energy and once the vibrations start, it can be nearly impossible to stop them. Thick carpeting is used because it absorbs these vibrations. There is no sound when walking on thick carpet.
To be effective, don’t just nail sheets of drywall to the existing wall surface. Sound will travel through the wall to the drywall. You need to create two completely independent wall sections. Make sure the studs aren’t directly across from each other. For best results, studs should be staggered across the length of the wall. A concrete surface at the bottom of the wall helps prevent sound from reaching the other wall and ultimately, your room.
The space in between is filled with sound proof material. Insulation can be used and is usually sprayed or blown into the area between the sections. You could also use foam insulating material or wool. Be sure to leave several inches of space between the two walls for absorbing the noise adequately.
Because Americans are living longer lives and the baby boomer generation is getting older and requiring more health care, there are many medical jobs in demand. As demand for health care grows, there are more people needed to provide medical care as well as perform the administrative functions that go along with it. Whether you are looking for an entry level job or are considering what kind of medical degree to pursue, you will find many choices in the health care field.
Physician assistants are becoming more common in doctors offices and this job field continues to grow very fast. This person performs many of the same tasks that the physician does, but they work under the doctors supervision. You can become a physician assistant in approximately two to three years. The duties that assistants can do varies from state to state. Some are able to write prescriptions without a doctors signature while others cannot.
As the health industry grows, there is becoming a need for more medical secretaries. A medical secretary does administrative tasks and can find employment in doctors offices, clinics, hospitals and nursing homes. A degree or certification is not required to be a medical secretary, but as the job market becomes more competitive, the person who has taken some medical secretary classes will have the edge. You will also need to have good office skills.
For hospitalist jobs like medical assistants, they handle some clerical duties like a secretary, but they also perform some basic procedures. The assistant may take a patients temperature, blood pressure and medical history. They may also draw blood for lab testing. It will take approximately ten to eighteen months to become a medical assistant.
As more people need health care, there is a greater need for physicians, surgeons, and nurses. To become a physician or surgeon, you will need to complete four years of college, four years of medical school and another three to eight years for residency training. It will take four years to become a registered nurse. You can become a licensed practical or vocational nurse in twelve months to two years time.
There is also a lot of work available for pharmacists. Because a pharmacist is a doctor of pharmacy, extensive schooling is required. You will spend around 8 years in college to become a pharmacist. They are assisted by pharmacy technicians and pharmacy assistants. The technician works closely and under the guidance of the pharmacist. It is possible that you could land a job as a pharmacy technician without any formal training, but you will have a much better chance if you become certified. The assistant, on the other hand, handles public contact and other administrative type duties so this is usually an entry level job. Because the pharmacy assistant is usually the person who has first contact with the public, strong customer service skills are helpful.
Some jobs in the health care field can be done from home. Although many are employed in traditional health care settings, some medical billers and medical transcriptionists work from their home. Completing training and working in an office setting as a biller will help you hone the skills you will need to be successful working as a biller out of your home. In order to become a medical transcriptionist, you will need to complete training and you need to have a good understanding of medical terminology. People that are medical transcriptionists can work in offices or from home.
There are many choices for the person just beginning their career or for those who want to try something new. With lots of medical jobs to pick from, it is really up to you to decide which career path fits your interest and qualifications that you have or are willing to attain.
Essential Reality Check No. 1 – The Type of Pet for kids
The type of pet you can take into your household will depend on a whole host of things such as follows: How much will the pet costs be – not just to buy – but to care for on a daily basis? The ages of your kids – a two year old child will probably not be able to handle a pet gently and certainly won’t be able to care for the pet….. What size of pet does your child want? – What space will be needed? A hamster does not take up much space but guinea pigs, ferrets and rats need much larger cages. How much time do your kids and you as a family have to give to the pet? Will your family be safe with the pet?
Will the pet be safe with your family? If you have a larger pet such as a dog, cat, or goat what effects will it have on your family, friends and neighbours? How will your pet be cared for during your holidays. Will your family be able to cope with the eventual death of a pet? Some pets will sleep most of the day and be awake at night. Hamsters can be very noisy at night! If your child wants a dog you will need to look into the breed, size and exercise needs of the dog. Do you already have another pet, what effect will it have on that pet. For instance will your dog be ok with a cat or rabbit or bird? .
Essential Reality Check No. 2 – True Costs of Pets for Kids
Some pets are very cheap to buy for instance hamsters, guinea pigs, goldfish. gerbils, fancy rats, fancy mice and rabbits and even ferrets. You will still need to consider: The cage set up ( this can be very expensive when looking at the cage sizes that most pets need) in fact they need the largest cage you can manage Food costs per week Bedding Vets bills if your pets become ill. e.g. Ferrets need a yearly injection against canine distemper. Holiday care – you will need to pay for this of course if you cannot rely on friends and family.
Bigger pets such as goats, and dogs and pedigree cats are far more expensive to buy initially, some costing hundreds of pounds. You will need to consider: Bedding and a cage (if buying one for your dog or cat) Leads and collars for dogs. Food bills Vets bills (dogs should have yearly check ups with a vets) Toys Holiday care (kennels can be very expensive) Flea treatment Ongoing veterinary costs if your pets becomes chronically ill.
Essential Reality Check No. 3 – Ages of your Kids
As the parent or carer you will need to decide if your child is old enough to handle and care for a pet. How often have parents heard the cry “oh but we promise we’ll take it for walks everyday” Or “we’ll clean it out mum, we promise”. How will you feel in a years time when you find yourself caring for the pets because the kids are busy with friends or away on a school trip or inundated with homework or just plain bored with the poor thing You will need to decide on a pet that is suitable for the age of your kids. For instance in most cases it would not be wise to buy a hamster for a two year old child who is still adapting to the world around them and may not know or be able to handle the hamster gently.
Do you want to give your kids some responsibility in caring for an animal. Some kids are very responsible and will be able to manage this. Other kids, well the sight of a baby animal is just too appealing, after all who can resist a cute puppy or kitten or baby hamster? At first you may need to help your kids, as caring for a pet is a very responsible job. As a parent or carer you will always need to oversee a pet’s care.
,Essential Reality Check No. 4 – The Space Required
Even small pets for kids such as guinea pigs, fancy rats and ferrets need a lot of cage space for a happy life. They will need the biggest cages you can find space for. These pets also need space to exercise out of the cage. Cats take up very little space, as do small breeds of dogs. Dogs will need a decent sized garden as well as walks to keep them well exercised.
Essential Reality Check No. 5 – Time for your Pets
Do you and the family have time for a pet. For smaller pets for kids you will need to have them out of the cage and being handled daily for at least 2 hours a day. Do you have time to clean out your pet at least once or twice a week, or even daily? Some pets will certainly need the toilet corner of their cage cleaned more often to avoid a foul smelling cage and pet. Water bottles and food bowls will need cleaning and refilling every day.
Will you be able to walk your dog at least once a day? – dependent on the breed some need more! Are you willing to look after your pets for the many years some can live? (From 18 months to 2 years for a mouse up to 15 years for a dog) If you are out at work all day and the kids are at school all day your pets will need and will demand attention when you return home
Essential Reality Check No. 6 – Your Pet and Family Safety
You will always need to ensure your kids safety when they are spending time with any pets for kids. Even little pets can bite and leave a wound. Dogs should not be left unattended with your kids as they are unpredictable. Even a faithful dog will bite and even attack a child if they are in pain or afraid. It happens rarely – but it does happen. You will also need to ensure your pets safety: Is your child able to handle a pet safely without hurting it. Is your pet safe with any other pets in the home? – if you have young children and a dog …. you will need to make sure the dog cannot escape because a door is accidentally left open.
If you have a dog you need to ensure visitors safety as you can be sued if your dog bites someone on your property (or even off your property) Make sure that when pets are having free time out of cages that: Other pets cannot hurt them They cannot chew electrical leads They cannot fall into toilets or baths of water. They cannot escape through gaps in walls or floors They cannot get outside without supervision
Essential Reality Check No. 7 – Effects on Family and Neighbours
The whole family needs to be in agreement if you are getting pets for kids. Pets can be noisy and messy having an effect on family living. What effect will a pet such as a dog have on Granny who suffers with an allergy – will that mean she cannot come to visit anymore? If you get a dog will it bark and howl when you leave them for any length of time and will this annoy your neighbours. Will the dog bark when your neighbours are in their own garden. How will your neighbours take to having your pet cat mess in their garden? You will need to keep your yard free of dog mess to ensure it does not smell -particularly in summer months.
Essential Reality Check No. 8 – Holidays and Care for Pets
If you have pets for kids what will happen to them during your holiday times. Do you have family or friends who can care for your pets while you are away. If not you will have to pay for your pets care. This will be expensive for dogs, cats and larger animals. Even for little pets, holiday care can be expensive.
Essential Reality Check No. 9 – Loss of a Pet and Grief
Some children are really sensitive and will be distraught when their beloved pet eventually passes away, or is lost in some way. This is especially distressing if the pet has died as a result of an accident or illness. How will you manage this? The kids will need to grieve, grieving is a healthy part of a loss reaction. We can suffer losses every day in a small way such as not getting something we want, this causes a loss reaction and part of the healing for this is grief. If your child or other family member struggles with the grieving then look at the following and see if it applies. The grieving process has seven stepping stones through which people move. Your family member may not go through them in order or spend long on any one.
The stepping stones are: Shock, Denial, Guilt, ,Anger, Depression Bargaining, Acceptance Your child may want another pet this is called bargaining and is one of the stepping stones through the grief process. If your child cannot have another pet, break down the hidden losses that the death of their pet has caused. Could there be a loss of your child’s self worth or self esteem. Have they lost their only companion. Has your child lost the only one who listened to them. By chatting try to find out how your child is feeling and help them to work out their losses and then work through to acceptance by doing some healthy bargaining.
Would your child be able to regain their sense of worth or self esteem another way? Perhaps helping out with a friends pet for instance. For some children it may be helpful to have a burial service, so they can say goodbye properly. (My son kept some hair from his beloved dog) Our kids have managed the deaths of their pets really well and have gone on to have other pets, for other kids though it has more of an effect so you will need to decide when or if to replace your child’s pet.
Essential Reality Check No. 10 – Pets for Kids are GOOD FUN!!!
Pets for kids are for the most part a great addition to the family.. They are often good company for your kids especially if the kids are lonely. Kids can learn a lot from caring for pets and by having pets even when they are lost naturally. Dogs can encourage the family out to get exercise as they walk the dog. All our kids love their pets and they are an important part of the family. So whatever pet you decide upon have fun and enjoy
“The roots of education are bitter, but the fruit is sweet.”
How was the day of your little wonder when he went to school for the first time in his life? Shedding tears, screaming to go home, gazing at other tots-imitating them or start getting anxious? An euphoric aura envelops around the enthusiastic parents. Whatever it takes, everyone wants his or her child to be a part of the educated society. But providing education doesn’t include just fetching him admission in a good school. It involves tedious activities, especially when the school starts. Whether your child is going to school for the first time or going back to school from a long summer vacation, he has to be well equipped with the requirements needed at school. Providing kids with best schooling, best requisites and giving him efficient knowledge at home is not cakewalk. The students also take grave pain in completing their primary and high school grades throughout their childhood and tweenhood. However, the result of sincere and competent learning recompenses the efforts and pain taken by the parents and the students in unison.
You may want to give him the best possible stationery products that also suit your pouch simultaneously. Best quality books, pencils, geometry cases, sharpeners, Tiffin boxes, water bottles, school bags and so on. You might consider spacious school bags and high-grade water bottles for your child’s lunch requisites.
Often, attention is given mostly to purchasing of notebooks and writing instruments. Pencil boxes sharpeners and erasers might get the surplus importance. About school bags, you may mull over the outward show, or choose a spacious bag at the most. The features for selecting a school bag that you think are worth a thought may not be enough. Certainly, the very appearance and the size matters when talking about school bags. But when you explore, you will find that a lot of brainwork is implemented to pick out the appropriate choice.
Appearance matters! There are a variety of contemporary school bags available to pick from. You might find it difficult to choose the right one. Carry your son or daughter with you-because appearance matters. You would surely not want the newly bought school gear lying around at home, unused. If you want to purchase it yourself, you’ll have to be familiar with your kid’s choice-which can be risky. If you bought a bag with the latest cartoon characters embedded and if your son is a sport and sportsmen buff, then it is certainly a waste. Bags for young boys are available in cool colors with cartoon characters or sports’ illustrations. For young girls, bright colors, floral prints and cartoon characters are found on their school bags. But interests can be different with different kids. They might not follow the contemporary trend and want a design or a color, which can be unusual. For example, a girl may show distaste for girly shades like pink and blue. She may want something more smarts, boy-like and not typically girly.
Suppliers offer school bags with variety animal motifs, and environ-friendly symbols as well. Many companies manufacture models in association with PET, PU and TPU. School bags are also made with embellishments out of embroidery, beads and metals. Bags attached with stuffed plush toys are certainly alluring for the kids-they can remove the soft toy and play with, during their leisure. However, the look of the schoolbag is not enough to be considered. The other crucial aspects need added attention.
Consider convenience! Children are gripped with severe back problems due to very heavy school bags that they carry to school on a daily basis. They are forced to carry weights that they can’t carry off easily at their age-this in turn affects their fragile shoulders adversely. It is however recommended that school-going children must not carry more than 10-20 percent of their weight.
Manufacturers realize the children’s plight. Thus backpacks are available for maximum convenience. Backpacks are suggested for school going children since it allow spreading out the weight on both left and the right sides. An enduring school backpack has strong, padded and foam-cushioned shoulder straps, which are at least 3 inches wide. Makers of school bags also offer waist belts and straps for added support to the back, thus distributing the weight of the bag evenly. You should take the size of the bag into consideration. Let it not be overtly large or small. Moreover, to check the fitting and the grip, you may ask your child to wear the bag and adjust the straps according to his size. Encourage him to carry off the bag on both the shoulders to avoid stressing one shoulder.
Backpacks are available with wheels and handles too. But you must check with the school’s guidelines if they allow such a kind. However, dragging a wheeled bag for a long time may hurt children’s joints and arms. While considering these trolley backpacks, pay heed to the wheels and the handles-they shouldn’t be heavy. Dragging and carrying conversely can reduce the burden.
While we talk about sturdy straps and handles, it becomes imperative to choose a durable material too cause school bags go through enormous wear and tear every school day. Carriers for school requisites are known to be durable when they are both made of sturdy belts and long lasting material. School bags made of leather must be avoided at all costs to pass up the extra weight of the material, though it’s a robust pick!
Manufacturers offer school totes in lightweight materials such as nylon, canvas, PVC and microfiber, which also give durability. They are aware of the fact that school bags are meant to be getting dirty every now and then. They offer bags in easy-to-clean materials like nylon, PVC and water-resistant microfiber. Wash your son’s soiled school bag and get a new look every time.
Gone are the days when you saw students carrying dual compartment school gears. The age speaks of multi-tasking, multi-talent, multi-uses and multi-compartments. This encourages added filling. But if the bag is of an appropriate size, multi-compartments can organize the student’s varied items efficiently. These bags mostly come with durable zippers and the pockets help in organizing beverage containers, lunch boxes, umbrellas and much more. Novelty does not end here. They are available with straps that have compartments for stuffing cell phones mp3 players or I-pods. Multi-compartment school bags are available in different shapes and types.
It’s not just about convenient bags. You might want to purchase a school pack that should at least last a year. You want to pick the one that is also not heavy on your purse. But this doesn’t mean you opt for a cheap one, because it may hardly last a few months. Again, picking a super costly bag is not a wise decision, reason- the style of the bag might become outdated in a year or two, and your child may not want to use it any more. Moreover, the required size for a school bag can vary with time. A moderately costing school bag, with a design of your kid’s choice and a durable material with efficient usability will not be harsh on your pocket.
The variety is enormous, which one do you want? One of the most stylish ranges of bags that are in demand would be messenger bags. Those who do not want to show the bulky look of backpacks; they opt for swanky messenger bags. These bags are carried one-sided, useful for carrying school and college requisites. They can also be used for travelling and moderate shopping. Messenger bags or haversacks can be multi-flapped with varied pockets of different sizes. You can carry your books and files safely. However, messenger bags are not advisable for children who have to carry a heavy load of books. Since their shoulders and back are fragile, the excessive load will strain one of the shoulders causing severe damage. In fact, messenger bags are meant to carry little or moderate weight.
A modish version of backpack is a sling bag. Also, it rests on one of the shoulders like a messenger bag, carried crossed. However, the sling bag rests on the back and doesn’t hang out on the either side. This bag can give good grip. But one cannot carry many loads, since the bag rests on one of the shoulders. This bag is preferable for carrying moderate or fewer loads. Sling bags are carried more for a trendy look.
Girls at school carry horizontal bags. If your girl child wants to be girly, a horizontal bag is most suitable. These book bags are available in attractive colors, floral prints, and pictures of Barbie and cartoon characters. Horizontal/rectangular bags do not have many compartments unlike backpacks. However, when you’re young lass is growing older and when she is about to go to high school she won’t want to carry the horizontal bag anymore. Horizontal school bags are for small schoolgirls.
Backpacks are a common form of school bags carried at school, liked by both boys and girls. Backpacks have provisions for multiple compartments. Moreover, different styles of backpacks give grip differently. Vest packs, rucksacks, hug bags are some of the styles of backpacks available for school going children. They have technical suspension system that reduce back and shoulder fatigue. To give added benefits, manufacturers have new ways to fulfill the demands of the school going wonders. This multi-utility luggage’s can be undoubtedly used for various other purposes, for e.g. travelling, hiking, adventure trips and other picnic excursions. So, if your child is going for a trip to the mountains with his school gang, you need not worry about purchasing a new bag for his expedition!
Waterproof school bags are an inevitable requisite where people experience rainfall. Children have to take care of their books and notes when they travel from home to school and come back. Waterproof bags are made of lightweight materials like nylon, polyester, microfiber and DWR-treated fabric. However, the material alone doesn’t protect your belongings. These bags have rain-guard zippers that don’t allow water to seep in and the bag has no open ends to allow water to leak in. water proof school bags are available of all types and shapes. These bags have replaced book bags made of jute, leather and denim.
Get Sporty! When was the last time you played a sport? It is hard to remember, isn’t it? But you can’t ask this question to a kid, because it’s his age to play and almost every day. Kids have to play to stimulate their minds and for physical growth and fitness. If he goes to the club to play tennis, you can’t expect him to carry his school bag, even though a backpack can serve the purpose. Buy him a duffel bag or a sports backpack. These bags are spacious and also available in waterproof style. Therefore they can serve students who go for swimming as well.
Trading school bags! A utility product, bags and school bags form an important feature of ‘back to school’ shopping in almost every household. The market for manufacturing bags for export is huge in regions like China and Taiwan. In India, the demand for school bags is huge for the locally manufactured ones, moreover due to their low price ranges. There is a niche demand for export brand school bags here in India, restricted to a few, due to their relatively high price ranges. Most of the bag-producing companies in India are adopting synthetic leather, denim and canvas for production purposes. Fabrics to make school bags are mostly soured from the local textile providers in Delhi, Uttar Pradesh, Gujarat and West Bengal. An Indian brand, D.M.Pakitwala, has created an image not only in India but also overseas for its quality and innovative designs.
The U.S. construction industry complies with national model and local building codes. The importance of code was highlighted during the tragic events in Italy in early 2009. A Reuters article blamed “less than scrupulous respect for anti-seismic building codes” for the collapse of a hospital built in the year 2000 in the region. Similarly, if you compare the number of car crashes on the news daily to the number of fires, and you also get a sense of just how effective and necessary these codes are. Unfortunately, building designs optimized for fire safety often work against good acoustical performance. In other words, fire and sound aren’t usually building compatible.
When designing for quiet, the industry often references the Gypsum Association Fire Resistance Design Manualto determine the best way to create noise reduction for occupants while still keeping the design in compliance with fire codes.
The Gypsum Association’s publication references the industry’s most pervasive noise control requirements, Sound Transmission Class (STC) Ratings, as a way to determine the success of noise damping design. The generally accepted rule is that the higher the STC Rating, the better the design. In many cases, model building code dictates an STC Rating of 50 or higher. For designing adequate noise proofing, when it comes to STC ratings, there aren’t a lot of other measurement options or guidance on the right level to target.
Understanding STC Ratings
But as an industry, we need to consider that much of the foundation for the STC Ratings system is dated. Testing and lab results in the Gypsum Association’s manual are more than 40 years old. The STC Ratings system was developed post WWII for typical household noises such as conversation, dishwashing, and music from a radio. It takes into account frequencies down to 125 Hz. As machinery advanced, trucks grew, home theaters bloomed, and subwoofers became ubiquitous, noises below 125 Hz became common and STC Ratings are now less an indicator of quiet.
In order to best understand how to maximize the value of STC Ratings, it is helpful to understand how STC is calculated for a particular wall assembly. The STC value is a calculation based on the ASTM Standard E90. STC is somewhat like how the EPA calculates the miles per gallon performance of vehicles. Even though the sticker may state “28 MPG”, results will vary based on speed, driving situation and vehicle condition. If you have one gallon left in your car, and the nearest gas station is 27.5 miles away, chances are, you’re not going to risk the drive.
Similarly, STC Ratings are not the most precise way to measure sound damping, but it gives a usable scale. However, if you want to address noise in a particular frequency range (i.e., low frequencies or high frequencies), it is smart to consult the actual transmission loss (TL) curve to identify exactly how the wall assembly performed in those frequencies. This will let you predict more accurately the results you can expect from the assembly in your project. STC value calculation ignores TL below 125 and de-emphasizes frequencies 500 Hz and below. If your project will need to control noise at these frequencies, the calculated STC value would not be a particularly valuable criterion for predicting the performance of an assembly for your project.
Another potential complication is that a variable of less than 5 STC points either way doesn’t make a huge difference in how people hear noise. Even if you’ve designed for an STC rating, STC Ratings of 50 in the lab generally get built to 45 in real life. Let’s say your design is 3 STC points short of meeting code, you may change that design to comply with code. The technical requirements will be met, but the owner or occupants may not experience the expected “comfort.”
The most noticeable changes of STC Ratings are greater than 5, and a 10 point difference can be like turning off sound to the human ear.
The Institute for Research in Construction conducted a study that found the point at which sound insulation starts becoming effective is approximately STC 55, or to put it even more simply, STC 55 makes people happy. If we design for an STC 60, it follows that as an industry we will end up with an STC 55 in the field. But STC 60 doesn’t happen with traditional wall construction. To get to STC 60, builders need an acoustical consultant or other field expert to help.
Noise Reduction Design Solutions
Experts can help determine the best way that sound transmission control solutions could work for your project. For example, one common method is to add mass; another is to use structurally independent leaves. When working with mass law, each time you double up a layer of similar mass material, you can gain up to 6 STC points. This principle works on that fact that the heavier an object is, the more energy it takes to vibrate it. Movie theaters have used this design process for years, some walls between screens are up to 3 feet thick with many layers of concrete block and then faced with multiple layers of drywall–sometimes 16 to 20 layers on each side of the CMUs . Structurally independent leaves work by separating the sound control from the structure.
Another method uses damped layer panels. Damping technology is not new. It has been used in planes, trains and automobiles for years to increase cabin comfort. It hasn’t been used in construction until recently due to many factors. It can be a messy process, end results are not ascetically pleasing, or it could not package in either in an easily usable form or application methods would be difficult. In the past few years, however, solutions that are easy to use, reliable and ascetically pleasing are now available.
Caulking is an absolutely critical component of a high TL wall. During building, a common occurrence happens when the contractor ran out of caulk as he was nearing the end of the job. He may have had every intention of finishing but may have been distracted or forgot to come back to that spot. By missing that spot, the resulting STC is 10 points lower than specified. The real problem comes into play at the time of occupancy because at this point, the performance is not being tested.
So far, we have focused on wall assemblies and code. It is important to note that controlling noise with floor and ceiling assemblies is another type of challenge. Floor and ceiling assemblies are rated on two independent codes: STC and IIC. You now know what STC measures airborne sound transmission. IIC stands for Impact Isolation Class and it measures structure-borne sound transmission.
IIC is calculated similarly to how STC is calculated with a number of values resulting from tests at various frequencies. However, there is some dissatisfaction with the IIC measurement today. Some of the most common complaints about noise involve what is often called “high heel” noise, which occurs at high frequencies. Many experts believe that the current IIC measurement under-weighs high frequencies, so that a high-IIC floor/ceiling assembly will not always solve the problem of “high heel” noise.
We expect that a growing movement to modify how the calculation is made will soon effect changes that will allow IIC to provide values that more closely fit builders’ expectations.
Another, sometimes overlooked, way to help with sound control simply has to do with orientation within the environment. You can use the features of the surrounding rooms to assist in lowering sound transmission.
How the ductwork runs are done can have a dramatic impact. Sound will take the path of least resistance. Some fairly typical designs provide a direct pathway for sound to travel from room to room. A better way would be to run ducts along a hallway and then trunk them in and out of each room.
Just like the previous example door orientation can make it easy for sound to travel between rooms. Locating doors away from each other or diagonally opposed will definitely help.
Code Plus Design for True Value
A perceived savings by engineering for “value” up front could lead to an added liability exposure to all involved. Plans are developed without considering acoustical function of space. Noise issues are not realized until there is occupancy and then there is usually no budget set aside for remediation.
An upfront investment to consider acoustical function can generate a serious return on investment. Noise mitigation costs 10% as much at the design phase rather than the build phase. In other words, delaying the design of noise mitigation until the build phase can increase the cost of implementation by 10 times.
Most all of us are affected by noise or sound in and around our buildings. The best designs incorporate sound management into the overall design solution. Acoustics needs to be not only considered but incorporated at the very start of a design project—just as other building sciences are utilized during the design phase.
Today, I would urge acoustical designers to use STC Ratings and other codes as a tool to use as a general indicator of ‘goodness’ but not a detailed picture of owner satisfaction. The ultimate proof is in the performance of a wall, and that usually means implementing an overall acoustic design at code plus.