Silent Floor Ultra Acoustic Underlay | 5.2kg/m² Composite | 1200mm x 600mm x 11mm
Silent Floor Ultra is a composite acoustic underlay combining a 5kg/m² mass loaded vinyl barrier bonded to a layer of 25kg/m³ closed-cell cross-linked PU foam. The two-layer construction addresses floor noise through different mechanisms simultaneously: the MLV barrier mass resists airborne sound transmission through the floor structure, while the closed-cell foam layer absorbs and dissipates impact energy before it can travel into the structure below. Laid beneath carpet, the composite delivers 42dB of impact sound reduction — significantly higher than standard carpet underlay alone.
The underlay is supplied in pre-cut 600mm x 1200mm tiles. Each pack contains 5 tiles covering 3.6m². The tile format simplifies handling and cutting to fit around obstacles compared with roll stock, and reduces waste when working in irregular or compartmented spaces.
Applications
- Separating floors in flats and apartments — the primary application. Between an upper floor flat and the flat below, impact noise from footsteps, dropped objects, and furniture movement is the most common source of noise complaints. Silent Floor Ultra replaces standard carpet underlay, upgrading the acoustic performance of the floor build-up without structural alteration. UK Approved Document E requires a maximum impact sound level of 62dB Ln,w for separating floors — Silent Floor Ultra should be specified as part of a full assessed floor build-up to achieve compliance.
- Upper floor rooms in houses — under carpet in bedrooms, living rooms, and home offices positioned above other occupied rooms. Where standard underlay is not providing sufficient impact noise reduction, Silent Floor Ultra is a direct replacement that adds meaningful acoustic performance to an otherwise standard carpet installation.
- Rental properties and HMOs — where carpet is a tenancy requirement and impact noise between floors is a recurring issue. Silent Floor Ultra fits within a standard carpet installation and requires no structural work, making it suitable for occupied or tenanted buildings.
- Commercial carpet installations — in offices, hotels, and commercial spaces where carpet is specified and floor-to-floor impact noise must be minimised. The tile format is well suited to commercial spaces with irregular room layouts, columns, and service penetrations.
Product Benefits
- 42dB impact sound reduction. Standard carpet underlay typically achieves 15–25dB impact sound reduction depending on density and thickness. The addition of the 5kg/m² MLV barrier layer substantially increases performance by adding mass and decoupling the carpet from the subfloor structure.
- Composite construction — impact and airborne in one layer. Standard carpet underlay addresses impact noise only. The MLV barrier component of Silent Floor Ultra also resists airborne sound transmission through the floor structure — conversations, music, and low-frequency noise from below. A single 11mm layer replaces what would otherwise require two separate products.
- Direct replacement for standard carpet underlay. Silent Floor Ultra installs in the same way as conventional carpet underlay — no additional products, specialist tools, or structural alteration required. Carpet grippers and the carpet installation follow the same process as a standard fit.
- Pre-cut tile format — 600mm x 1200mm per tile. The tile format is easier to handle, transport, and cut than roll stock. Offcuts from one tile can be used elsewhere in the installation, reducing material waste compared with roll cutting.
- 11mm nominal thickness. Door clearances and transitions to adjoining floor types should be checked before installation, particularly in renovation projects where the existing floor level is close to the bottom of the door.
- Closed-cell cross-linked PU foam. Does not absorb moisture, resists compression set under sustained load, and maintains acoustic properties over time. Dimensional stability of 2% at 100°C ensures consistent performance in rooms with underfloor heating.
Installation
Lay tiles foam-side up, MLV-side down to the subfloor. The subfloor should be clean, level, and structurally sound before installation — any movement or irregularity in the subfloor will reduce the effectiveness of the acoustic layer above it. Apply contact adhesive around the perimeter of each tile and at butt joints to prevent movement during and after the floor covering installation. Stagger tile joints by at least 150mm and ensure all joins are flush before laying the floor covering on top. At 11mm, check door clearances and transitions to adjoining floor types before committing to the installation.
The Technical Details
| Product Name | Silent Floor Ultra Acoustic Underlay |
| Product Size | 1200mm x 600mm x 11mm |
| Tiles Per Pack |
5 |
| Area Covered Per Pack | 3.6sqm |
| Hardness |
76 (Durometer Shore A, 1 sec dwell) |
| Tensile Strength |
0.9mpA (JISK6251) |
| Elongation at Break | >100% (JISK6251) |
| Dimensional Stability | 2% (4hr @ 100oC) |
| Surface Tension | >44 dynes/cm |
| Product Colour | Grey |
| Product Weight | 5.2kg/m2 |
| Fire Classification | <100 mm/min (FMVSS 302) |
| Impact Sound Reduction | 42dB |
