Soundproofing works on a simple principle: mass blocks sound. The heavier and denser a wall, floor, or ceiling is, the harder it is for sound waves to make it vibrate and transmit through to the other side. The problem is that adding mass the traditional way — thicker blockwork, more concrete, heavier plasterboard — means structural work, planning, and significant cost. Mass Loaded Vinyl was developed as a practical alternative.
MLV is a dense, limp, flexible membrane — typically 1–3kg per square metre — that can be applied to an existing surface to dramatically increase its mass without significant structural change. Laid over a floor, attached to a wall frame, or hung as a barrier curtain, it adds the blocking mass that airborne noise needs to lose its energy passing through a surface.
How MLV works
Sound travels through solid structures because the surface vibrates. The heavier a surface is for its thickness, the less it vibrates at a given sound pressure level. MLV is engineered to be as dense as possible in as thin a layer as possible — the limp, non-resonant construction means it absorbs vibrational energy rather than amplifying it (which some stiffer materials can do).
MLV is most effective against airborne noise — voices, music, traffic. It is a mass layer, not a decoupling system. For impact noise (footsteps, dropped objects), mass alone is only part of the solution; see Resilient Clips & Channels or Acoustic Underlay for the decoupling component.
Installation disruption level: low to moderate. MLV can be applied to existing surfaces (glued, screwed, or hung) or incorporated into a new wall or floor build. No structural work required for surface application, though access to the full surface is needed.
Typical use cases
- Leasehold flats and rented spaces — MLV adds mass to party walls and floors without permanent structural modification; can be removed when you leave
- Home recording studios — applied within the wall framing of a studio build, combined with acoustic mineral wool fill and resilient clips for a complete isolation system
- Plant rooms and mechanical enclosures — wrap noise-generating equipment in MLV barriers to contain machinery noise within the enclosure
- Commercial tenancies — add mass to lightweight partition walls between offices or meeting rooms without landlord consent for structural alteration
- Beneath floor boards — laid under floor boards or over joists before the finished floor, MLV adds mass to the floor build without increasing floor height significantly
Technical notes
MLV is measured for sound transmission performance under BS EN ISO 717-1 (airborne sound insulation, expressed as Rw). Performance varies by mass per square metre — heavier products provide greater sound reduction. Published Rw data is available on request for specification purposes. Part E of the Building Regulations sets minimum sound insulation requirements for new builds and conversions; MLV is commonly specified as a mass-addition component in Part E compliant wall and floor systems.
What's the difference between MLV and acoustic membranes?
Both are flexible, dense barrier layers used to add mass to a building element — and the terms are sometimes used interchangeably by suppliers. In practice, Mass Loaded Vinyl is a specific material type (a PVC-based composite loaded with mineral content), while acoustic membranes is a broader category that includes bitumen-based, rubber-based, and other polymer barrier materials.
The performance difference is marginal for most applications. The practical distinction is in how they are applied: MLV is typically used in flexible, hung, or removable configurations (barrier curtains, under-floor applications, lining existing walls); bitumen-based acoustic membranes are more commonly specified in fixed construction builds — under screed, within floor systems, in wet-room situations — because they are easier to fully adhere or bond in place. See our Acoustic Membranes page for more detail on that product category.
Not sure which product is right for your situation? Get in touch and we'll advise on the best specification for your build.