Footsteps and chair scraping from upstairs: what can be done?
The short answer
Footsteps, scraping chairs and kids running are impact noise (footsteps through the floor slab). The impact enters the floor finish first, then travels through the RC slab to the unit below, so the most effective place to treat it is on the source side. The V-CORE vacuum-layer insulated soundproof floor adds a thin decoupling and vibration-damping functional layer between the floor finish and the RC slab, and breaks the bridges around the edges. When you're about to redo your own floor, that's the lowest-cost time to do it. The V-CORE floor sound insulation system has received the Taiwan High-Performance Green Building Material Label.
Key points
- First, tell them apart: footsteps and running are impact noise (through the structure); talking and TV are airborne sound (through the air).
- Impact noise has to be treated at the point of impact, which means the floor build-up of the unit above.
- Thicker tiles or wood flooring alone may not help. The key is whether the finish is decoupled from the slab.
- The edges matter most: if the finish touches walls or door thresholds without a break, it forms a sound bridge.
What's the difference between impact noise and airborne sound?
| Type | Common sources | How it travels | What to treat |
|---|---|---|---|
| Impact noise | Footsteps, running, chair scraping, dropped objects | Impacts make the floor slab vibrate, and the vibration travels through the structure | Add a decoupling and vibration-damping layer between the finish and the slab |
| Airborne sound | Talking, TV, stereo | Sound waves pass through the slab and gaps | Add mass, airtightness and multi-layer design |
| Flanking transmission | Walls, beams and columns, pipes, door frames | Bypasses the main sound-insulating build-up | Treat sound bridges around the edges and pipe penetrations |
Why treat it on the source side?
The energy of a footstep enters the floor finish first, then passes into the RC slab. Breaking the direct path between the point of impact and the slab works better than trying to fix it from the ceiling below.
If you're about to redo your own floor, that's the lowest-cost time to add a sound-insulating floor build-up. If the noise comes from the unit above, treating only your own ceiling can help only so much, and we'll explain this clearly during the site visit.
Common mistakes
- Just switching to thicker tiles or wood flooring: If a hard finish is in rigid contact with the slab, impacts still go straight into the structure.
- Laying an acoustic underlay but not treating the edges: When the finish touches party walls, columns or door frames, sound goes around through the edges.
- Wet installation letting mortar seep into joints: Once it hardens, it forms a sound bridge and the decoupling layer stops working.
How the V-CORE vacuum-layer insulated soundproof floor is built
The V-CORE vacuum layer sits between the floor finish and the RC slab as a thin decoupling and vibration-damping functional layer, forming a complete build-up together with the damping layer, leveling and finish. A typical tiled build-up (top to bottom):
- Tile: Wear-resistant, decorative finish
- Tile adhesive: Bonding and local leveling
- V-CORE vacuum layer: Thin decoupling / vibration-damping functional layer
- RC slab: Load-bearing and main mass layer
Other finishes such as SPC and wood flooring can also be used, but each case has to be designed around the finish's rigidity, loads, flatness and installation method.
The V-CORE floor sound insulation system has received the Taiwan High-Performance Green Building Material Label.
Key installation points
- Substrate preparation: Remove dust and sharp protrusions, confirm there's no ongoing water seepage, and control flatness.
- Perimeter isolation: Place cushioning material first at wall-floor junctions, column edges, door frames and around pipe bases.
- Continuous laying: V-CORE is laid flat and continuous, with seams closed according to the method and no gaps left.
- Finish and edge details: Skirting boards, thresholds and cabinet bases must not bridge the finish and the slab.
Where it fits and its limits
Suitable for: homes about to redo their floors, renovations of older homes, spaces with limited ceiling height and threshold height, and spaces that want to reduce impact noise with a thin build-up.
Limits: Sound insulation is a property of the complete floor system and depends on RC thickness, the finish, perimeter detailing, pipe penetrations and continuity of installation. Material performance is not the same as completed-system performance, and the slab condition, the extra height available and threshold details still need to be confirmed. Floor sound insulation in new construction is subject to separate regulations; please check whether they apply with the latest rules of the authority where the site is located.
What affects the quote and schedule, and what counts as handover?
The main factors in the quote are:
- Area and floor finish: tiles, SPC and timber floors use different build-ups, materials and steps.
- Existing floor: whether it must be removed, and how much substrate levelling is needed.
- Edges and thresholds: buffer treatment at walls, columns, door frames and pipe penetrations, and whether thresholds or doors need adjusting.
- Available height: this decides which build-up can be used.
Re-flooring is often scheduled together with other renovation work; the actual schedule is explained after the inspection, based on the finish and site conditions.
What counts as handover:
- Documents: material model and thickness match the drawings.
- Substrate: flat, clean and free of ongoing seepage.
- Laying: V-CORE is continuous and flat, joints are tight, with no damage or local crushing.
- Edges: no rigid contact at walls, columns, door frames or pipe penetrations.
- Finish: no abnormal hollowness, warping, level differences or cracks.
Footstep noise is not judged by how it sounds to someone. If the contract sets a sound insulation target, the supporting report or on-site measurement method must be agreed at the design stage.
FAQ
It's noisy upstairs. What can I do in my own home?
Impact noise is best treated at the floor of the unit above. What you can do in your own home is a double-ceiling system and treating flanking paths, which helps only so much. We'll explain this clearly during the site visit.
How much will the floor be raised? Will the doors need changing?
V-CORE is a thin functional layer, but the total thickness also includes the adhesive and the finish. Whether thresholds and door leaves need adjusting depends on the heights on site.
Can it be used with wood flooring or SPC?
Yes, but each case has to be designed around the finish's rigidity, loads and installation method. Not every finish can be laid directly on it.
Is there test data?
The V-CORE floor sound insulation system has received the Taiwan High-Performance Green Building Material Label. Completed results depend on the overall build-up and workmanship, so we don't make promises based on a single decibel figure.
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