21mm Karma Visco Acoustic Overlay Board 1200x600mm

Karma Visco Overlay boards are top-quality acoustic panels designed for renovation projects that require a shallow floor build up and where an existing floor surface already exists. These boards incorporate internal strips of viscoelastic adhesive that absorb sound vibrations and prevent them from reaching the building structure, resulting in exceptional acoustic performance. Additionally, the boards have a cushioning resilient layer that minimizes impact sound transmission and accounts for any small inconsistencies in the subfloor. All products come factory-bonded for convenience.

Application & Installation

• Storage:
  • To ensure optimal performance, all components must be stored indoors, covered, and kept dry. Panels should be stacked flat on a level surface. It is recommended to move the materials to the environment in which they will be installed at least 24 hours before installation.
• Subfloor Tolerances:
  • The evenness of the subfloor must not exceed +/- 2mm per 2 metre run. Additionally, the base floor must be clean and completely dried out. Any pipes, fixings, or obstacles should be cleared from the floor prior to installation.
• Installation:
  • Place Karma isolation tape between Karma Visco overlay boards and perimeter walls during installation. This will reduce flanking sound transmission.
  • Lay Karma Visco overlay boards as shown in the illustration with the grooved edges or cut edges facing the perimeter walls. Use the offcut from the final panel in the first row to commence the next row. Do not start a row with an offcut less than 250mm long. Lay panels in a brick-bonded fashion.
  • While laying boards apply a liberal amount of Karma PU adhesive to the grooves of the T&G joint and tightly butt the boards together. Wipe off excess adhesive with a damp cloth. Avoid walking on the boards until the adhesive has dried.
• Floor Coverings
  • For thin floor finishes, such as vinyl or linoleum, it is recommended to overlay the Karma Visco overlay boards with a 6mm plywood or hardboard layer to prevent joint mirroring.
  • When tiling with ceramic floor tiles, it is important to lay them on a flexible stress-relieving membrane and fix them with flexible bedding compound and grout. For natural stone finishes, like marble, granite, and limestone, it is advisable to seek professional advice and lay them according to the supplier's recommendations.
  • If you plan to install carpet over Karma Visco Overlay Boards, it is recommended to glue the gripper rods to the surface instead of nailing them to prevent damage to the underlying structure.
  • For wood flooring, it is not recommended to nail it to the Karma Visco Overlay boards. It's important to seek advice from the wood suppliers before installation to determine the best method of installation, and ensure this layer is isolated from walls.