Condominiums in multi-family buildings offer many advantages to their occupants over single-family homes. Unfortunately, acoustical privacy is often not one of those advantages. When sound control is not a priority in the design and construction of these buildings, it often results in owner complaint and, in worse cases, condo owner vs. building team litigation. The International Building Code, IBC 2000, requires IIC (Impact Insulation Class) and STC (Sound Transmission Class) ratings of 50 or greater. High-end condominiums often design for 55 and 60 ratings as a minimum.
Guidelines for sound control between units are given below. A qualified acoustical consultant will best provide the system approach needed to look at all potential noise issues.
Floors and Ceilings - Performance will vary based on the base structure; concrete, wood frame, post and beam, and the like. Where hard surface flooring is installed, impact noise needs to be attenuated. Sound control underlayments are installed between the structural floor and the finish floor to provide resilience and an acoustical break in the floor buildup. Generally, thicker is better. Kinetics Model SR Floorboard is a high-performance underlayment at 5/8" thick. Model Soundmatt (5/16") and LP Soundmatt (3/16") are successfully used where a lower profile and lower cost floor assembly is desirable. For exposed timber (loft), or any floor requiring optimum STC and IIC improvement, see Model Ultra Quiet SR and Model RIM floating floors.
In wood frame construction and in many concrete deck assemblies, a gypsum board ceiling is an important part of the sound control assembly. Isolation with a resilient hanging element will greatly improve both airborne and impact-generated noise control.
The Model ICW spring and neoprene hanger and the Model IsoMax neoprene isolation clip are both designed for wood frame ceiling attachment. Model ICW offers optimum performance. Model IsoMax provides improved field performance vs. resilient channel and is very economical. Both are UL listed in a variety of assemblies. See UL Design L583 for IsoMax and Design L581 for ICW hangers.
Ceilings suspended from concrete deck can use any of the following models depending on allowable ceiling drop and low-frequency isolation requirements. Note: Springs outperform pads as ceiling isolators for attenuating low-frequency sound.
Walls - Using IsoMax Clips improves steel or wood stud wall STC ratings 5-7 points versus resilient channel. With IsoMax you can match double stud wall performance in a single stud assembly saving 33% of your valuable floor space.
Note: For isolation at the base or top plate of stud walls, see Model Wallmat to control sound flanking.
Note to designer: Isolated ceilings produce more sound reduction in lower frequencies while typical 3/16" - 5/8" underlayments produce mid and high frequency attenuation. Floor underlayments also minimize impact noise flanking to adjacent rooms and the room below. In many applications a system combining both will provide the best overall noise reduction.