Silent Floor Ultra Acoustic Underlay | 5.2kg/m² Composite | 1200mm x 600mm x 11mm | Bulk Pallet — 100 Sheets
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.
This is the same product supplied in the standard 5-sheet pack, available here as a full pallet of 100 sheets for flooring contractors, acoustic installers, and developers working across multiple units or large floor areas. 100 sheets provides 72m² total coverage at a total pallet weight of approximately 374kg. Delivered kerbside on a full pallet.
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.
- 72m² per pallet — trade quantity pricing. A full pallet of 100 sheets eliminates the per-pack premium and reduces material cost per m² on multi-unit residential, commercial, and contractor projects. Sheets from the same production batch ensure consistent specification across the installation.
- 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.
- 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 — any movement or irregularity will reduce the effectiveness of the acoustic layer. Apply contact adhesive around the perimeter of each tile and at all butt joints to prevent movement during carpet fitting and subsequent foot traffic. Stagger tile joints by at least 150mm. Fix carpet gripper around the room perimeter in the usual way and fit carpet over the top as standard.
The Technical Details
| Product Name | Silent Floor Ultra Acoustic Underlay |
| Product Size | 1200mm x 600mm x 11mm |
| Sheets Per Pallet |
100 |
| Area Covered Per Pallet | 72sqm |
| 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 |
