Architectural acoustics and the control of noise within buildings have advanced more rapidly than computer technology in the past ten years. Fifty years ago, construction professionals tried to minimize the transfer of noise by adding more mass to a structure (thicker walls) or by building two walls parallel to each other with dead space in between. These early construction methods were ineffective in controlling noise, they added significantly more materials to a structure, were expensive to build and not environmentally friendly.
The building industry was primed for noise control products that could deliver acoustical performance. Today there are specially engineered drywall and plywood products; [1] adhesives and sealants, [2] as well as isolation clip designs. [3] Prior to 2000, there were no rubber isolation systems available in the marketplace to dampen the transmission of sound.
The Sound of Silence
editIn response to the needs of the building industry the Resilient Sound Isolation Clip was introduced in 2000 as the first rubber isolator. RSIC-1 was engineered to provide noise control, be both cost effective and environmentally friendly, and exceed building codes for fire and sound as set forth in the International Building Code.
Since its introduction, RSIC products have become a benchmark for acoustical noise control solutions and the manufacturer, PAC International, has become a sought after resource on acoustical technology for building applications.
- RSIC-1 product and test data are being included in college textbooks to assist academia in the study of noise control. [4] [5]
- Architects, engineers, builders and industry trade associations look to knowledgeable and resourceful PAC International technicians for information and education. [6]
- RSIC University was launched in 2007 to provide a online course on Sound Attenuation. This free, one-hour course is accredited by the American Institute of Architects, the Construction Specifications Institute and other organizations that serve architects, engineers and construction professionals.
- RSIC-1 is the only noise control product classified by Underwriters Laboratories (UL) for both fire and sound.
- RSIC-1 is UL Classified for use in over 75 fire resistive design assemblies. RSIC data is published in the Underwriters Laboratories Online Certifications Directory [7] and the annual print edition for fire resistive designs.
Use in Construction
editRSIC products can be attached to a wall stud (wood or steel frame), concrete, concrete masonry unit and floor-ceiling assembly. RSIC products are used in construction projects where sound transmission is a concern, such as on a common wall between two apartments units. The purpose of the RSIC product, when combined with furring channel, is to provide a means for affixing drywall to the supporting structure. By not allowing the drywall to contact the supporting wood, metal or concrete, improved acoustical performance is achieved. In other words, sound transmission between walls and footfall noise between floor-ceilings are dramatically reduced.
RSIC products are incorporated into designs/drawings for residential and commercial buildings by architects and/or acoustical engineers. One of the responsibilities of the architect or engineer is to ensure that the building meets both fire and sound ratings as specified by the International Building Code, and state or local building codes that may also be applicable.
Once the building project has been approved and construction begins, RSIC products will be installed after the framing phase but prior to installation of drywall. Installation is typically performed by drywall subcontractors. RSIC products are installed in lieu of resilient channel (RC-1), a product developed in the 1960s by United States Gypsum Company, a subsidiary of USG Corporation. The reason for the substitution is that RSIC products are specifically designed to minimize sound transmission through a wall or floor-ceiling assembly, while RC-1 [8] was not originally intended for sound minimization purposes.
Once a structure is built, an independent acoustical engineer may go to the job site to perform field testing. Field testing is conducted to measure the sound transmission between rooms and dwelling units in order to determine if the Sound Transmission Class (STC) and Impact Insulation Class (IIC), also known as Impact Isolation Class, have been achieved as set forth in the building code.
The STC rating is a measurement of airborne noise while the IIC rating determines how effective a floor-ceiling structure is at stopping footfall noise.
For example, in a series of field tests, an independent engineering firm tested RSIC-1 against RC-1. The tests for floor-ceiling assemblies showed that RSIC-1 outperformed RC-1 by 16 points or 160%. RSIC-1 delivered an IIC of 60 compared to RC-1 which had an IIC of 44. [9]
There are different STC ratings that may need to be met depending on the structure being built. For example:
- Apartments, Condominiums and Hotels/Motels – Separation between dwelling units and between dwelling units and public and service areas must achieve an STC of not less than 50 [10] and an IIC of not less than 50 [11] (45 if field tested).
- Commercial Buildings – Separation between sensitive areas like a business conference room and an adjacent tenant should have partitions with an STC of 56 to 64.
- High-End Hotels and Luxury Condos – An STC of 65 to 70 is desired on partitions between hotel rooms or condos to significantly reduce noise transmission.
- Single Family Housing – Separation between a bedroom and a home theater that includes high-powered theater and stereo equipment should ideally be STC 70 or greater.
Product Testing
editRSIC products from PAC International are manufactured in the United States and undergo multiple tests and procedures, including:
- Fire Code Rating - Testing is performed by Underwriters Laboratories for product safety to receive a fire rating for a fire resistive design. UL Classification is based on standards and test procedures developed by Underwriters Laboratories.
- Strength Analysis - Load and stress tests are performed by Testing Engineers Inc. This materials testing laboratory applies loads to both RSIC products and structural assemblies. The analysis provides data as to when the product or assembly yields to stress, the point of failure, and when safety margins are met or exceeded.
- Acoustical Performance – Testing is performed in an acoustical testing laboratory, such as Riverbank Acoustical Laboratories or Western Electro Acoustical Laboratory. These facilities conduct tests to determine sound absorption, sound transmission loss, airborne and structure borne noise and other acoustical properties. This testing serves to ascertain both the STC and IIC ratings.
See Also
editAcoustics
Architectural acoustics
International Building Code
Room acoustics
Sound transmission class
External Links
editAcoustical Society of America
American Institute of Architects
National Council of Acoustical Consultants
PAC International, Inc.
Testing Engineers Inc.
Underwriters Laboratories
Footnotes
edit- ^ QuietRock or Supress Sound-Engineered Products
- ^ Green Glue or QuietGlue
- ^ IsoMax by Kinetics, WhisperClip or Genie Clips.
- ^ Long, Marshall. (2006). Architectural Acoustics. PAC International test data included in Chapter 12, “Noise Transmission in Floor Systems,” page 430. Elsevier Academic Press. ISBN 13: 978-0-12-455551-8.
- ^ Gervais, Rod. (2006). Home Recording Studio, Build It Like the Pros. RSIC-1 product featured in Chapter 4, “Floor, Wall, and Ceiling Construction Details,” pages 57-59. Thomson Course Technology and Artist Pro Publishing. ISBN: 1-59863-034-2.
- ^ Gernhart, Elzo F. The Journal of the Acoustical Society of America, September 2005, Volume 118, Issue 3, pages 1919-1920. “Case study of modifications to a wood 'I' beam framed floor-ceiling assembly which did not meet minimum International Building Code (IBC), impact insulation class (IIC) or sound transmission class (STC).”
- ^ The UL Online Certifications Directory is searchable and can be used to verify a UL listing or classification, a UL listed product use, and verify a product safety standard.
- ^ The original RC-1 product is no longer being manufactured.
- ^ IIC field test results for RSIC-1 and RC-1.
- ^ International Code Council, Inc. 2003 International Building Code. Chapter 12, "Interior Environment." Section 1207.2 Air-borne sound. ISBN 1-892395-56-8.
- ^ International Code Council, Inc. 2003 International Building Code. Chapter 12, "Interior Environment." Section 1207.3 Structure-borne sound. ISBN 1-892395-56-8.