Roof Curb Isolation Rail

A noise and vibration control system that goes beyond internal isolation.

KSR Roof Curb Rail


Kinetics Model KSR Isolation Rails are specifically designed and engineered for use as a noise and vibration isolation system for roof curb-mounted mechanical equipment.

Model KSR isolation rails are compatible with most roof-supported equipment and standard roof curb systems without modification and provide support, noise and vibration isolation, and an air and water seal for supported equipment.

Typical applications include support and isolation for unitary-packaged air-handling and refrigeration equipment, and exhaust fans, ordinarily mounted directly on non-isolated roof curb systems.

Model KSR isolation rails significantly reduce noise and vibration transmitted from rooftop equipment into roof structures by using equipment weight as an inertia mass to load high-deflection, free-standing, stable springs integrated with the continuous aluminum isolation rail system.


Kinetics KSR Isolation Rails are the next generation isolation system designed and engineered to isolate packaged rooftop equipment from the roof structure. Designed for easy installation, minimum interference with equipment overhang and with accessible springs, the Kinetics KSR goes well beyond internal isolation by reducing casing-radiated vibration caused by turbulent air flow as well as compressor and fan vibration.

KSR rails have a positive elastomeric air and weather seal permitting the inside of the unit to be used as a return air plenum. The KSR mates with the inside of the manufacturers' curb eliminating any internal interference. The KSR also features an impressive family of options including:

  • Aluminum weather seal flashing
  • Seismic restraint
  • Airborne noise control package
  • Duct blockoffs
KSR Isolation Rail


Spring components shall be (1"/25 mm), (2"/51 mm) deflection, free-standing, unhoused, laterally stable steel springs. Springs shall have a lateral stiffness greater than 1.0 times the rated vertical stiffness and shall be designed for 50% overload to solid.

Springs shall be color coded to indicate load capacity.

Rails shall provide continuous support for the rooftop equipment and shall be designed to provide isolation against casing-radiated vibration in the rooftop equipment housing and structureborne vibration from rotating and mechanical equipment in the rooftop package.

Rail assembly shall consist of extruded aluminum top and bottom members connected by spring isolators and a continuous air- and water-tight seal. The seal shall be a beaded elastomeric material retained in a keyway along the top extrusion. The weather strip shall be sealed along the bottom with an aluminum fascia strip.

Rail assemblies shall incorporate means for attachment to the building and the supported equipment and shall incorporate additional stiffening members if necessary to assure stability.

Vibration isolators shall be selected by the manufacturer for each specific application to comply with deflection requirements as shown on the Vibration Isolation Schedule or as indicated on the project documents.

Roof Curb Rails shall be Model KSR as manufactured by Kinetics Noise Control, Inc.

Mechanical Systems

Vibration Isolation Seismic & Wind Noise Control