All in Agreement: Sounds Ugly
Summer run Steelhead fishing in Washington State is a new hobby I picked up. It’s an unbelievable rush to have a 10 or 15 pound Steelie on in fast water. Our boat is drifting slowly in the current and I cast upriver allowing my bait to sink when all of a sudden the fight is on.
All you can hear is the water rushing by the boat, eagles and ospreys screeching overhead and your heart pounding. The fish blasts out of the water 3 feet and you see that it’s big and its chrome bright and you realize that the fish has more of you than you have of it, especially knowing that only an 8-pound test leader is holding him back. All you can do is let it run and keep upward pressure on the hook by keeping your rod tipped up.
In all this natural beauty, another boat heading up river rounded the bend. You could hear it coming like thunder in the distance. As it approached us at about 45 mph, the noise coming from its big V-8 jet drive was deafening. One moment I’m in a quiet paradise fighting the biggest, meanest Steelhead in the river and the next I’m wanting to cover my ears while fighting my fish.
Each person’s idea of paradise may be different but most will agree that home needs to be that place where people can retreat to peace and quiet. People who live in multi-family situations as in condominiums, apartments or duplexes expect the same peace and quiet that other people find in single-family homes.
Noise coming from the unit above, below or from the sides of another person’s living unit has got to be irritating. For the homeowner, the noise is an irritant; however, it’s the sound of money to law firms who specialize in noise defect lawsuits. Please read the following information from Terry Kastner, technical consultant with the Northwest Wall and Ceiling Bureau.
“Along with the ever-increasing construction in condominiums has come a heightened awareness and demand for construction methods that will reduce the transference of sound. In addition to the building developers retaining the services of a building envelope consultant they are also retaining Acoustical Consultants to ensure that sound dampening systems are installed in a manner consistent with documents. For the most part, it is our responsibility to construct sound partitions so as to conform to the details provided by the architect/acoustical consultant. In this case as in many, the devil is in the details and it is usually the little things that are forgotten and come back to haunt us. In many cases the ‘little thing’ is the proper application of sound sealants.
“The first essential for controlling sound is to close off air leaks and/or flanking paths by which noise can go through or around the system. Small cracks or holes that allow the passage of air will increase sound transmission. For a sound partition to be effective the system must be airtight. This means that all wall fixtures, electrical and/or mechanical devices that penetrate the gypsum board must be sealed and cannot be located back to back within the same stud cavity. Flexible sealants or acoustical gaskets must be used to seal between the partition and all dissimilar surfaces and also between the partition and similar surfaces where perimeter relief is required. In addition to acoustical sealants and gaskets, taping gypsum board wall and wall-ceiling intersections provides an adequate air seal.
“The following question came up recently: In above ceiling conditions, on a non-fire rated partition, must the vertical drywall joints that occur over framing members be sealed? The question came about because, on a fire rated partition above a fire rated ceiling system, the board joints and fasteners do not necessarily need to be fire taped, provided the vertical board joints occur over framing members. On a fire rated only partition, this is correct but only if the fire rated partition is not also a smoke or sound partition. If a partition is a sound or smoke control system it must be airtight and all joints must be sealed. Fasteners, when installed correctly, are self-sealing and do not require sealing.
“Sealing of the joints in a smoke/sound system may be accomplished by either applying a Level 1 finish (fire taping) or by using a flexible sound caulk.
“Remember to construct the partitions so as to be in conformance with the details provided in the construction documents and to seal the partition to an airtight condition.
“For more information on the proper construction of sound partitions, see ASTM E 497 Standard Practice for Installing Sound-Isolating Lightweight Partitions.”
Additional Sources: The Gypsum Association Fire Resistance Design Manual Sound Control
THERE’S A HOLE IN THE BUCKET
Typical ways in which sound travels in a building is via “flanking paths” or through unsealed openings. An example of a flanking path through a well-insulated sound wall can be via a structural column where noise hits the column thereby traveling to the unit above, below or to the side. In other words, sound can pass from one area to another via structural steel because it has less resistance than insulation. When you pour water into a bucket it will stay there unless there’s a hole in the bucket.
If air can pass through an unsealed opening so can noise and smoke. If a wall, floor or ceiling has “air leaks,” you can be sure it will have “noise” leaks. When wall and ceiling contractors bid projects that require certain sound transmission ratings be achieved, those design and construction methods must be followed. If construction requires caulking at the top and bottom of a wall it must be done to an airtight condition. If deflection is designed into a sound rated partition, you must use a sound caulking system that allows for compression and extension. When caulking a “static” top or bottom of wall, which is a joint that does not move, therefore is referred to as static, you must make sure that your caulking is adhering to the floor/deck and gypsum. Acoustical caulk rarely sticks to the cut edge of gypsum.
A “dynamic” top of wall joint, which is a joint designed to allow movement, is an interesting problem, which I think most of us haven’t given the condition the attention it deserves. On a dynamic top of wall joint if we sound caulk the top of the wall between the top of the sheetrock and the bottom of the floor deck and the floor moves downward; the sound caulking will compress and push outward. Then, and if the floor moves upward the sound caulking won’t extend thereby leaving an air and noise leak at the top of the wall. Sound caulking on walls that are designed to deflect should be done differently. The sound caulk should be done similarly to fire stopping where the caulk is adhered to the deck above and over the face of the drywall. Installing it this way will allow for true compression and extension.
TESTING IS EASY
To test a building and its walls, floors and ceilings for air leaks or noise leaks is not very expensive and relatively easy. It’s also easy to identify which subcontractor’s work is leaking. Leaks in electrical boxes can be separated from leaks at the top or bottom of a wall. Door leaks can be isolated from bathroom wall leaks. Plumbing noise leaks can be separated from ductwork noise leaks.
The owner or attorney hires a sound transmission consultant to verify that STC ratings have been achieved. Once they find that the overall STC ratings were not achieved the process of dividing up responsibility begins.
As Kastner says, “the devil is in the details.” In many cases the wall and ceiling subcontractor may not know their work will be tested at some point. If tenants of a building complain enough you can bank on an attorney specializing in noisy buildings becoming involved. I think we all agree that people who live in multi-family buildings have the right to peace and quiet, yet they need to realize they are not buying a sound studio where all noise is eliminated. There will be noise to some degree unless they are willing to pay for a sound studio.
All of us need to pay closer attention to sound related construction details and we need to share our concerns about sound transmission to our customers. Sound transmission cases could far exceed water and mold claims which would result in another huge insurance premium escalation. Make sure sound transmission coverage is not specifically excluded from your liability insurance policy and consider contract language that will protect you.
Remember: Teamwork begins with a fair contract! W&C