Traffic noise drives people mad, especially on Melbourne’s tram and arterial corridors such as Punt Road, St Kilda Road and Sydney Road, and in Tasmanian homes that face faster-moving routes near Hobart or Launceston. There is no single silver bullet, but a smart combination of measures can transform a room. The most important and most overlooked piece is sealing.
Most homeowners jump straight to glass. Double glazing is great at stopping sound through the pane. But in traditional double hung sash windows, much of the remaining noise comes around the pane through the small operating gaps at the stiles, the meeting rail, and the frame. Those gaps make the sash slide, and acoustically they are open doorways. This is why many Melbourne terraces and Tasmanian cottages do not get the acoustic payoff they expect after a glass only upgrade.
Seal the gaps and the glass can finally do its job.
Key takeaways for Melbourne and Tasmania homes
- Double glazing blocks sound through glass, but unsealed gaps let noise bypass it. This is a common issue on busy Melbourne streets and on highway situated Tasmanian properties.
- Purpose designed twin fin draught and acoustic seals in sash windows can cut bypass noise significantly. Lab results show about six to ten decibels for the brush system alone, depending on installation.
- For heavier traffic or tram rumble, pair sealing with acoustic laminated glass or vacuum glass for the best results.
- Thermal comfort improves as well. If air cannot leak in, neither can cold or heat, which helps in Melbourne winters and in Tasmanian southerlies.
Where the noise actually gets in
- Stiles and parting bead: continuous sliding gaps on both sides of the sashes
- Meeting rails: the joint between upper and lower sashes
- Bottom rail to sill: often an unsealed path directly into the room
Glass is a barrier. A gap is a shortcut. Even a tiny gap can undo expensive glazing upgrades, whether you are beside Punt Road in Melbourne or the Tasman Highway in Tasmania.
What we fit and why it works
At Sealasash, our motto is no seals no deal. Every project includes draught and acoustic sealing because that is where sash windows are weakest.
Twin fin brush seals are installed
- in the staff bead on the room side perimeter
- across all parting bead sections between the sashes
- in a parallel row at the meeting rail
Each brush has a raised central fin that splits into two as it deflects, creating multiple layers of barrier with a controlled air gap. When the meeting rails close, you get stacked layers which disrupt airflow and sound paths. In lab conditions, twin fin brush systems have shown about six to ten decibels of acoustic effect for the seal itself. Real world performance varies by window, fit and background noise.
Optional bottom rail acoustic seal
On the bottom sash we often add a twin fin compression seal on the bottom rail. When the sash closes, it forms a firm contact with the sill, blocking a common leak path and complementing the sliding seals. It is a small detail with an outsized effect, and it is great for front rooms in Brunswick and Fitzroy terraces or in Sandy Bay and Battery Point cottages that face traffic.
Proof you can hear
We have demonstrated this sealing approach at trade shows with heavy bass music in a display cabinet. People are surprised by how much a properly sealed window blocks. For real world clips, see these examples for hinged and sash windows:
- Facebook demo: https://www.facebook.com/watch/?v=582644306491866
- YouTube demo: https://www.youtube.com/watch?v=FACGzlRbuxc
- Double hung demo on Melbourne’s Punt Road on Instagram: https://www.instagram.com/reel/C86oxYVv4oJ/?hl=en
For a broader look at soundproofing that includes walls and doors, there is a case study from my own home beside a 100 kilometre per hour highway on www.vacglass.com.au.
Independent guidance and endorsement
- Draught proofing science. Heritage research shows that professional draught sealing can slash air leakage in sash windows, improving acoustic and thermal performance.
- Acoustic engineer endorsement. Our twin fin sealing strategy for sliding sashes has been endorsed by Sydney based acoustic engineer Peter Knowland on a Surry Hills building impacted by traffic noise. We follow these principles daily across Greater Melbourne and Southern Tasmania.
When is glass the limiting factor
Sealing tackles bypass noise first. On high exposure sites, such as tram lines, bus lanes and construction corridors in Melbourne, or homes within earshot of Hobart’s Brooker or Tasman Highways, upgrading the glass itself may be necessary.
- Acoustic laminated glass: uses a damping interlayer to reduce vibration. In some cases it outperforms standard double glazing for noise
- Vacuum glass such as Panasonic Glavenir: delivers outstanding thermal performance and excellent acoustic results in slim profiles which suit heritage frames common across Melbourne and Tasmania
If your current double glazing was not acoustic rated, sealing first, then targeted glass upgrades, is usually the most cost effective path.
Why Sealasash does it this way
We began as sealing specialists long before we added glazing. After more than twenty thousand sash windows and hundreds of public reviews across Melbourne and Tasmania, our stance is clear. Quality without compromise. We would rather do the fundamentals properly than sell you a pane that cannot perform because the frame leaks.
What results to expect
Every house and noise source is different, but homeowners typically report
- noticeably quieter rooms.
- fewer draughts and steadier temperatures.
- smoother sash operation with balanced tension and no rattling!
Numbers note. Sealing alone of about six to ten decibels at key frequencies is achievable in lab tests for the brush system. Real world results vary by window condition, fit and background noise. Sealing plus acoustic glass compounds the benefit, which is handy for inner Melbourne arterials and for Tasmanian homes located near highways or inner suburb lanes.
Local FAQs
Will double glazing alone stop tram and traffic noise
It helps, but if your sash still has unsealed operating gaps, sound will go around the pane. Sealing closes those bypass routes so your glass investment pays off. This is crucial on Melbourne tram routes and Tasmanian arterial roads.
Can sealing make windows hard to open
Not when done correctly. Our seals are chosen and tuned for low-friction sliding with a controlled air gap.
What about thermal performance
Sealing is a win here as well. If air cannot leak, heat and cold struggle to get in or out. That is useful in Melbourne winters and in Tasmania’s colder snaps.
Is this heritage friendly
Yes. Our approach retains original timber frames with reversible components. Slim acoustic and vacuum glass options suit heritage streetscapes across both regions.
