Soundproofing plastic
windows

Why street noise gets through your windows and what actually reduces it. A practical guide to glazing, profiles and installation details that make a flat quieter.

OKNA PLAST builds soundproofing plastic windows at its own workshop in Astana and installs them with its own crews. Quiet comes from a glazing unit with different glass thicknesses, a multi-chamber profile and a warm installation seam made to GOST with 9-point seismic safety. Free measurement starts the order.

Why you hear the street and where soundproofing plastic windows noise actually enters

Street noise in apartment rooms rarely comes through the glass alone. It enters a flat by four routes at once, and until you know which one dominates in your rooms, any upgrade is guesswork.

Four paths street noise takes into a flat

Street noise reaches a flat by four routes at once — the glazing unit, the sash rebate, the installation seam and the ventilation channel — and the loudest route is not always the glass. A single-chamber pack 24 mm thick passes low traffic rumble differently from a two-chamber assembly at 32–40 mm, yet a sash that does not press the gasket tight can leak more than either. The mounting joint matters just as much: a gap in the foam or a cracked seal at the frame edge turns the whole opening into a membrane. The vent channel is the fourth route, and it often stays open around the clock. Before ordering anything, stand by the window with it closed and listen with the vent flap shut; if the sound drops sharply, most of the noise arrives via ventilation, not the window.

Why wind and panel blocks make it worse

In Astana the strong wind adds a whistle on top of traffic rumble, and panel blocks carry sound via shared walls and shafts as much as via the window itself. Gusts load every joint at once: the sash rebate, the frame-to-wall perimeter and the vent grille all start to leak air, and leaking air carries sound with it. A panel building spreads that energy further, because the wall panels and the ventilation shaft act as a single connected path between neighbouring flats. A whistle that appears only in gusts usually points to a loose rebate or a gap along the perimeter, not to thin glass — fixing the gasket often removes the whistle before any glazing upgrade. Mounting joint layers and airtightness at the wall opening are set out in GOST 30971.

What really makes them quiet

Soundproofing plastic windows works through mass, through glass of unequal thickness inside the sealed cavity, and through a sash pressed tightly against its frame. Below we break down which of these three carries the most weight against traffic hum.

Why different glass thicknesses beat identical panes

A glazing build with unequal glass thicknesses — for example 4 mm and 6 mm — damps sound better than a build with identical panes, because the glasses resonate at different frequencies and do not pass the same noise together. A pair of 4 mm panes shares one resonance point, and traffic rumble around that frequency slips through almost untouched. Spacing matters as much as the numbers: a 4-6 combination in a 24 mm cavity handles low frequencies, while 4-8-4 in a 32 mm gap extends the effect across a wider band. Matching the panes to each other is the mistake most buyers make; asking for a 4-6 pairing instead of 4-4 costs nothing extra in most lines and audibly cuts traffic rumble.

How many chambers and how many decibels

A two-chamber pack holds three glasses and a pair of air gaps and clearly outperforms a single-chamber one, while profile makers quote figures such as up to 48 dB for Salamander bluEvolution, up to 46 dB for KBE 76 and up to 36 dB for WDS 6S. Those air gaps interrupt the sound path twice and add the mass of a third pane, which is why an acoustic build for a bedroom facing a busy avenue almost always means a two-chamber pack rather than a thicker single one. The decibel figures describe the profile system under test conditions, not your finished window; the real result depends on the glass pack and the seam, so treat the numbers as a comparison between lines, not a promise for the flat.

Choosing a profile and glazing unit for a home near a road

For a flat facing a busy avenue, soundproof glazing and the frame both decide the result. Below are the manufacturer's figures for the lines we build, so you can match them to the noise on your side.

Profile lines and what their numbers mean

Matching the glazing unit to the profile

We size the pack to the frame — up to 32 mm in the SMART line and up to 52 mm in Rehau Geneo — so panes of different thicknesses sit in the rebate without breaking the seal. The rebate and sash pressure set the limit: a 60 mm SMART frame carries a two-chamber 32 mm assembly, while Geneo accepts one up to 52 mm with three contours holding it. A thicker pack pays off only when the frame can hold it and the sash still presses evenly all round. Forcing a deep assembly into a shallow line trades acoustic performance for a draught at the rebate. On road-facing flats we pair mid-width frames with a proper two-chamber assembly rather than a very deep one with thin panes — the seam carries the low frequencies, and that pairing keeps the seal working through local wind.

What you can fix yourself and where DIY stops

Knowing how to make windows quieter starts with the parts you can fix without replacing anything — adjusting the sashes, renewing the seal and sealing gaps. Here is what a resident can do, and where a fitter is needed.

A self-check you can run in ten minutes

You can locate the weak point yourself by closing the window, shutting the vent, and listening at the rebate, the seam and the glass in turn — the spot where the sound is loudest is the one to fix first. Start at the sash rebate on a windy day: rumble that grows when the wind picks up usually points to the seal line rather than the panes. Next, shut the ventilation flap and check whether the rumble drops — if it does, the vent is the open channel, not the glazing. Then stand a metre from the glass and listen: a dull, even hum through the pane means the glass pack itself is the weak element. A sheet of paper trapped in the closed rebate that pulls out easily shows a loose press; that single test tells you whether adjustment will help before you spend on anything else.

What a seal change and adjustment can and cannot do

We see the biggest gains from a new seal and a proper sash adjustment when the noise comes through a loose rebate, but neither will quiet a thin single-chamber unit facing a busy road. Our after-installation service covers adjustment, seal replacement, handles and glass packs, and the rebate fix is the first thing a fitter checks on arrival. The seal matters twice over: it blocks the draught that carries sound and keeps the warm joint tight through the long frosty winter and strong wind. Adjustment and seal replacement are the cheap first step and worth doing before any glazing decision; if the rumble stays after the rebate is tight, the limit of DIY has been reached and the glass pack or the window is the next lever.

When to replace the whole window and when a glazing unit is enough

Sometimes a new glazing unit solves the problem, sometimes the whole window has to go. The decision rests on the profile, the seal line and the mounting joint — not on the panes alone.

Swapping only the glazing unit

We replace just the pack when the profile, the hardware and the frame are sound and the noise comes through the transparent part — the right glass thickness for quiet is what the new pack delivers — a fresh pack with panes of different thicknesses then does the job without touching the sash. A two-chamber pack of 32 mm with unequal sheets cuts traffic rumble far better than the original 4-4-4 sandwich, and the swap is done by our own crew. We keep the sashes, the handles and the sill, so nothing in the room changes. Before ordering, our engineer checks the seal line for even pressure and the hardware for a tight lock. Check the frame and that inner groove first; a new glazing unit dropped into a worn one keeps the old draught and the old noise, so the saving turns into a second visit.

When the whole window and the seam have to go

We recommend a full replacement when the profile is warped, the closing line no longer presses evenly or the mounting joint has failed — and in that case the new window is only as quiet as the airtight contour we build around it. Wind-driven noise sneaks past even a good window through that gap, which is why we make a warm joint to GOST with 9-point seismic safety and fit sills, flashing and slopes ourselves as part of the turnkey install; a balcony door in the same room is worth replacing together so the second contour does not leak. On the upper floors of the capital's towers the wind load is the deciding factor, and a fresh frame plus a sealed perimeter changes the result more than any upgrade of the panes. A balcony block replaced in one visit keeps the acoustic contour continuous.

What layers add up to a quiet apartment

Before you spend on anything, trace where the sound actually gets in — then fix that path. A quiet flat is a set of correct decisions, not one expensive purchase.

• Find the path first: check the glass, rebate, mounting joint and vent before deciding what to change, because a new unit will not silence a leaking gap.
• Mix the glass thicknesses: a build with layers of different gauge kills traffic rumble better than identical sheets of the same total weight.
• Read the decibels correctly: a two-chamber build and a multi-chamber profile both help, but the maker's figure describes the system, not your finished flat.
• Try the cheap step first: a fresh seal and a sash adjustment often remove a wind whistle on their own for a fraction of the effort.
• Replace the whole window only on failure: when the profile or the mounting joint has given up, a new unit alone is enough.