Do you have questions ?
A gym in a residential building. We do not publish the client’s name.
In the free-weight area, barbells and dumbbells of up to 120 kg are dropped from a height of up to 70 cm. The impacts travel through the slab as vibration and noise into the apartments.
First, we measured. With a Digiducer 333D01 digital accelerometer we recorded the response of the floor slab to an impact. The natural frequency of the slab is 15–20 Hz, and the vibration acceleration without isolation is 0.003–0.012 m/s².
This determines the solution: to isolate, the platform must have a resonance frequency at least 2.5 times lower than the slab, i.e. below 6 Hz. That can only be achieved with mass and springs.
We calculated 4 options for 5 impact scenarios. Besides the frequency, we checked the spring travel – if the platform is too light, the springs “bottom out” and pass the impact straight through.
The most effective option – spring isolators with a 100 mm concrete slab and elastomer layers on top – gives, by calculation, about 17.6 dB of isolation. An option with springs and plywood only gives 8.3 dB, because its resonance (7.8 Hz) is too close to the slab.
The client chose the simpler option: a stack of 10 layers of Sylodamp SP10 in a plywood frame, with rubber tiles on top. No concrete slab and no springs.
We say it plainly: the elastomer stack softens the impact and reduces the noise from it, but it does not isolate low frequencies the way a spring system does.
A barbell dropped on the gym floor and on the platform – first in the gym, then in the office next to it (the gym is visible on the CCTV screen). Recorded with a phone and the sound is uncorrected: it gives an idea, but it is not a measurement – the phone levels the recording volume by itself.
Similar problem? Contact us via the enquiry form.
The control measurement on 22.10.2026, after the platform was installed, showed peaks of vibration acceleration in the office next to the gym about 70% lower – approximately −10 dB compared with the measurement before (up to 0.012 m/s² when dropping weights of 60–120 kg). The value was read on site with a Digiducer 333D01 accelerometer.
The lesson from the project: in a gym inside a residential building, measure the slab first. Its frequency shows which solution is needed. Then the client chooses an option knowing in advance what each one delivers – in calculated dB, not in promises.
"*" indicates required fields
