Bitumen is an excellent sound-absorbing material for reducing structure-borne noise. This is precisely because it has a very high density. It is particularly effective at dampening vibration-induced noise. The material is flexible, making it easy to fold around corners, for example, when insulating a cabinet. There is probably bitumen under your kitchen sink at home—
—to dampen the sound of water hitting metal.
Available both with and without aluminum foil for additional thermal resistance.
Density: 3.5–7.5 kg/m²