Vibration isolation performance is the reduction of vibration passing from one building element into another.

The key measure is transmissibility. A low transmissibility value means less vibration is passing through the decoupling layer. Performance depends on the vibration frequency, isolator stiffness, supported load and damping in the connection.

Isolation usually starts once the vibration frequency is more than about 1.4 times the isolator’s natural frequency. For practical design, a ratio closer to 3:1 gives a stronger margin against resonance.

If the system is too stiff, vibration can pass through the connection. If it is too soft or poorly loaded, the construction can move too much and lose stability.