Multi-Family is wanting to go higher in the air. Typical construction projects in this last boom were 4 stories, combustible type 5 constructions. Sometimes there was a parking structure under them making for a higher platform but all in there was only four stories of living space. In order to go higher, a non-combustible metal system has been developed where the concrete portion is drastically thinner for flooring. This Corrugated Metal Deck system sometimes referred to as CSD or CMD is perceived to be quite noisy and costly for the installation of sound rated flooring. KEENE worked with a large installer of metal construction systems to solve the problem.
Commonly today, a two pour gypsum concrete system is used to control air and vibration noise. This two pour system fills the 0.625” flutes of the corrugated deck with high strength gypsum concrete, utilizing a binding agent to adhere the gypsum to the metal deck. After three days of hardening, the surface is ready to receive a sound mat and a final 1.0” gypsum concrete pour is added to the system. KEENE has the standard 3 product offering that will work in this system, including the new QUIET QURL 52/013 RF, QUIET QURL 55/ 025 MC and QUIET QURL 60/040 RF. With a 1.5” underlayment thickness, QUIET QURL 65 075 RF can be installed. In all, these products provide code compliant performance in properly installed applications and the thicker products can be expected to perform in the high 50’s range.
KEENE wanted more out of the system. Once again the solution was a “MT” system for the muffling technology KEENE has added to the bottom side of the sound mat. In this instance, the muffling technology also filled in the corrugated deck and allowed for one gypsum concrete pour. The thickness of the underlayment was enhanced to a total of 1.25”. The performance of the system was fabulous in the lab and the system earned an IIC (tested under ASTM E490) level greater than 60 with all finishes. KEENE worked with an acoustical consultant that recommended getting as much of the vibration noise out of the system at the source. Consequently, the high loft fabric not only limited the touching of the entangled net to the corrugated deck but also prevented the “echo” effect that minor contact with the decking system is known for in the field.
Subsequently, KEENE performed Robinson Wheel Testing (ASTM C627) and the system performed to an “EXTRA HEAVY DUTY” rating with ceramic tile. This is the same performance level has been approved in the typical assembly by Underwriters Laboratories with 2 layers of 5/8” gypsum board on the ceiling for fire purposes.
Sounds Good Doesn’t it?