ROCKWOOL Steprock HD is a very heavy-weight stone wool slab for for thermal, acoustic and fire insulation of floating floors in residential and commercial buildings. It is used installation under reinforced cement screeds and similar wet screeds. It prevents transmission of sound through the floating floor providing protection from air and impact noise. Steprock HD is used under concrete floating floors where extremely high loads are expected. Like all ROCKWOOL products it protects against fire; provides acoustic comfort due to its fibrous structure; is uniquely durable against all forms of weather and is only sourced from sustainable materials.