WestCon Tribune
October 1997
At the September Westcon meeting, speaker Fred Webster discussed the use of statistical sampling in conventional construction as it applies to the investigation of design and construction errors and failures. His talk covered acceptance sampling, sampling with risk assessment, sample sizes, confidence levels and population identification. He regrets that he was unable to answer all of your questions following the talk, but would be happy to address issues or concerns you may have regarding this subject.
Webster has over 25 years experience in civil engineering including structural analysis and design, applied probability and statistics, quality assurance and quality control, engineering evaluations, structural accident investigations, research, testing and teaching, and seismic rehabilitation of historic and older structures.
Webster spent four years as an Engineering Statistical Advisor to Texas Utilities during a comprehensive NRC review of design and construction adequacy at Comanche Peak Steam Electric Station. He developed and directed statistically-based investigations to address allegations of inadequate hardware and structure design and installation throughout the plant. He performed similar tasks at TVA's Watts Bar Nuclear Plant and PG&E's Diablo Plant. More recently, he has developed a statistical sampling insurance investigation of water intrusion problems at a large apartment complex in Marin County. He believes statistical sampling is a powerful tool that can be used to the advantage of construction consultants in both insurance and litigation issues.
This Month: Salter & Salter on Condo Acoustics
The October dinner meeting will host former Westcon President Charles M. Salter, P.E. and his son, Joshua Salter Berezin, Esq. The Salters will address condominium acoustics and the law. Charles, president of Charles M. Salter Associates, consultants in acoustics and audio/visual systems design, will discuss code requirements, market considerations, design challenges, construction issues, and acoustical factors that should be considered after tenants move in. Over the last 29 years, Charles has conducted a wide range of consulting work in the areas of architectural acoustics, noise control engineering, and environmental noise impact. He has had major involvement or project responsibility for assignments for hospitals, office buildings, schools, churches, theaters, and housing projects.
The esteemed attorney, Joshua Salter Berezin, Esq., will cover the legal factors involved in condominium acoustics including negligence, breach of contract/warranty, strict liability, and nuisance. Joshua is an attorney with Berding & Weil, and specializes in construction defect litigation and related issues.
The presentation will be enhanced with slides taken from Charles M. Salter Associates' much-anticipated reference book on acoustics, which is due out at the end of the year.
Acoustic Issues in Common Interest Developments - Is Your Development Too Noisy?
By Joshua Salter Berezin, Esq., and Charles M. Salter, P.E.
Noise from streets, neighbors, plumbing fixtures and machinery has become an ever increasing aspect of everyday life in the late twentieth century. While telecommunications companies take credit for making the world smaller, homeowners in common interest developments (CIDs) sometimes grumble at the reality of just how small their world has become. Small lot single family homes and multi-family housing is no longer a trend. These types of residences have become commonplace and will continue to be the dominant form of new construction. Smaller living areas necessitate a decrease in individually owned property and an increase in commonly owned property. This shared living space leads many homeowners to conclude that their neighbors create considerable and unwanted noise.
In most CIDs, homeowners frequently encounter unwanted noise intrusion through party walls and windows. Noise intrusion becomes an issue for boards and directors depending on the severity and frequency of the noise intrusion and the sensitivity of the homeowners who are affected by it. The purpose of this article is to highlight some of the causes of intrusive noise levels in CIDs and provide alternative means and methods for combating it.
Party Walls
A common complaint is that stereos and conversation can be heard through shared party walls. Most noise leaks can be solved by proper application of acoustical caulking and gasketing to each penetration before completing the wall. Failing to seal these penetrations can result in a five to fifteen decibel increase in noise transmission from unit to unit. A fifteen decibel reduction in noise transmission can be the difference between hearing a clear conversation from the next unit and having that same conversation be completely inaudible.
Fortunately for most homeowners, noise leaks are not expensive to repair. The acoustic caulking can often be applied by removing electrical boxes or phone jacks and then sealing those areas. The resulting decrease in noise transmitted between the units can increase property values and decrease homeowner disputes.
Plumbing Noise
A frequent homeowner complaint concerns noise generated by water and waste plumbing components. Complaints lodged by new condominium and townhouse owners are frequently described as "rattling pipes. Plumbing noise can be generated through a building's structure or through the pipes itself. Noise is substantially reduced at the outset of a project by installing resilient isolators between piping and the structural framing. To reduce airborne plumbing noise, the pipe should be at least one to two inches from the gypsum board in a neighbor's unit. A putty-like material can be used to suppress radiated noise when using plastic ABS wasted pipe or similar material.
Faulty or inferior plumbing fixtures can also create unwanted noise intrusion. Often when poor quality tub or shower mixing valves are use, there is a severe water pressure drop across the valves. The resulting vibration creates noise that is transmitted to adjacent rooms. Using higher quality fixtures or replacing existing fixtures can substantially reduce the noise caused by showers or baths.
Mechanical Noise
Many homeowners also experience noise caused by poorly installed or poor quality ventilation systems. When vent ducts are improperly installed, they will vibrate, conducting noise throughout the system. Other installation defects include installed ducts that are crimped, dented or have holes in them. These defects create noise when air is forced through a smaller opening. Installation factors create unnecessary noise and are difficult to fix. Many times the ducts will have multiple installation or quality issues. Each of the defective ducts must be located and addressed before the homeowner can be assured of a quiet system. This can be an expensive process because each of the defective ducts must be located by opening the ceiling and manually inspecting each section.
Windows
Many windows are not effective at keeping noise out. Windows that are typically installed in multi-family housing must achieve thermal protection to meet the energy code, but they can be inadequate for noise protection. This is particularly true if you have window that face a busy street or a parking lot, or if your home is near an airport or train track. One method of insuring that your existing windows provide maximum sound protection is to check their gasketing.
If, after replacing the gaskets, the noise intrusion is still at an unreasonable level, there are acoustically rated windows that can be installed to replace existing windows.
Floors
Many homeowners like the look and feel of hardwood floors. What they don't realize is that their new floor create additional vibration and noise in the unit below. Many homeowner associations have begun to protect against this problem by amending their CC&Rs to prohibit a change in flooring without prior approval. By including the types of flooring within the rubric of architectural control, a board can protect adjoining homeowners from noise caused by flooring not installed with sufficient noise dampening materials.
Failing to control the types of floors installed in CIDs can result in a painful lesson. In one recent case a homeowner sued his upstairs neighbor and his association's board of directors because of an allegedly unreasonable amount of noise created by his neighbor's new hardwood floors. The board had approved the installation of the floors without investigating the potential for affecting the downstairs neighbor's quiet enjoyment of his property. The homeowner successfully proved that the hardwood floors created an unreasonable amount of noise and that the homeowners association was partially to blame for approving the installation. After a three week jury trial, the homeowner was awarded $162,000. The jury determined that the homeowner association's board of directors was responsible for two-thirds of the recovery.
Design Concerns
Many homeowners have acoustical problems that could have been easily prevented during the design of the project. For instance, an architect should not place a kitchen, an area that creates impact noise, next to another unit's bedroom where a homeowner would rightfully expect a quiet area. Similarly, hard surfaced flooring should not be placed directly above a bedroom. If the preliminary design of a project demands that an area that generates noise must be located near an area where a reasonable person would expect quiet, additional acoustical treatments must be considered.
¥ This article appeared in the June 1997 issue of the ECHO Newsletter.
Member News
¥ Allied Builders of San Rafael has been selected as the general contractor of record to complete the $2.4 million retrofit project called The Beaches, Marina Bay in Richmond. Craig Poff has been appointed manager for the project, which consists of 133 townhomes and is scheduled for completion in March 1998.
¥ Ashok Kakade, M.S., P.E., will be instructing a UC Berkeley Extension class on October 10-11 entitled Concrete Technology. The two-day course is intended for construction professionals who are involved in construction, inspection, or repair of concrete structures. The course work is designed so that a person with no prior experience in concrete technology can understand and use the knowledge in day-to-day concrete work. To enroll: by phone 510.642.4111; by fax 510.642.0374; online unex.berkeley.edu:4243. If you have any questions, call 510.642.4151.
¥ Recently merged Fred Honeck and Harv Abernathey of Aquatech Consultancy will share their expertise with the Westcon membership at the November meeting. Honeck and Abernathey will discuss not only what they do but how and why they do it.
Code Committe Meeting Agenda: 15 October 1997
Westcon one day Symposium
The Board recommended that the committee proceed to write up the description of the symposium with prime topics, participants, schedule, budget, etc. for the Board's review. Discussion points included:
1. Symposium Title: "Design and Construction Defects in Frame Buildings: Why doesn't the industry get rid of them? What can be done to improve the system? Consider 2 formats:
a. Four to six panel discussions with lunch speaker.
b. Addresses by prominent developers, architects, and contractors in the morning, lunch speaker and panel discussion in the afternoon.
2. The Board requested that the participants all be Westcon members. Should the Code Committee request the Board to reconsider and allow non-Westcon members to participate?
3. Consider compiling a list of common deficiencies categorized by trades. This item has been discussed for several years at Code and Education committee meetings.
4. Consider suggesting to the Board and membership the following revisions to the purpose of the Organization:
Purpose
The purpose of this Organization is to promote the highest standards of professionalism and to protect the general welfare of the design and construction consultant, to improve the practice of the professional design and construction consultant, and to offer expertise and knowledge to the design and construction industry. Because of the Organization's unique experience of analyzing building failures and their costly legal ramifications, the Organization will attempt to suggest improvements to the design and construction industries.
Please join our discussion in person or write letters to the Westcon Tribune Editor expressing your opinion.
October Menu
Chicken Piccata with lemon juice and capers Filet Mignon Parisian Style served with artichoke heart madeira sauce Vegetable Crepes with roasted red pepper puree
Remember!! Late reservations or walk-ins (if there is space) will pay $33.
Please mark your meal choice and mail or fax your reservation with the names of those attending. Reservations must be received by Friday, October 10 1997, after which late fee will apply. Cost is $28 per member ($33 late fee) and $14 per first-time guest. Send payment and reservations to:
Lina Habache
Authentic Restoration & Waterproofing
1155 Chess Drive, Suite 116
Foster City, CA 94404
(415) 341-6932 FAX (415) 341-6733