Why Plastic Windows Let in Draughts in Minsk — Causes and How to Fix Them

The pace of technological progress in the 21st century is astonishing: we control computers with the power of thought and prepare to fly to Mars. Yet many of us still seal up our windows every winter, just like in the old days. We were assured that plastic windows are airtight and won't draught. However, draughts are one of the most common problems residents of Minsk and the Minsk district come to me with. So why do modern windows let cold in? There are many causes — from the simple ageing of the seal to serious installation errors or a manufacturing defect. There's no magic pill that gets rid of draughts once and for all. But if you correctly diagnose the cause, you can eliminate it completely and save a lot of money. I'm Dmitry, a window repair master with experience since 2003, and I've already helped hundreds of clients in Minsk and the region forget about draughts. In this article I'll go through all the possible causes of draughts and explain how to fix them.

A. Seal problems

Seal wear. Over time, especially on the sunny side, it loses its elasticity. Solution: replace it with a new, quality one (I recommend German brands REHAU, KBE, Schlegel).
Exposure to building dust. Cement, plaster and whitewash quickly dry out and ruin the rubber. Solution: protect the windows with film during a renovation, and use silicone lubricant for prevention.
Incorrect use of "winter mode". Rubber kept constantly compressed to the limit loses its shape. Solution: switch the cams to the winter/summer position correctly and replace the seal in good time.
Incorrect seal installation. Too taut, or conversely too long — it makes poor contact. Solution: correct fitting with trimming.
The seal slipping out of its groove. Often happens at the bottom of balcony doors. Solution: check it regularly and tuck it back into place.
Coloured seals. White and grey ones can stiffen in frost. Solution: choose black (it's more elastic), or fit quality EPDM straight away.
Co-extruded seals (welded into the profile). They're often less elastic in the cold. Solution: in some cases an additional seal contour can be fitted.

B. Hardware problems

Missing strike plates. Sometimes they aren't fitted, to save money. Solution: install the missing plates.
Poor assembly of the mechanism. If something is skewed during assembly, the pressure will be uneven. Solution: dismantle and refit the hardware.
Hinge offset during installation. This causes draughts in the corresponding corners. Solution: correct the hinges vertically/horizontally.
Use of the wrong screws. Metal screws hold poorly in plastic. Solution: replace them with special screws for PVC.
Wear of the mechanisms in the cold. Problems worsen in winter. Solution: regular servicing (cleaning, lubrication) and replacing worn parts.

C. Problems during glazing (fitting the glass unit)

Incorrect glass-unit installation. The support and adjustment plates (shims) are missing or wrongly placed. Because of this the sash can skew and a gap appear. Solution: correct re-shimming of the glass unit.

D. Manufacturing defects

A mismatch between the frame and sash sizes — for example, the sash is smaller than the opening. Solution: correction or replacement of the faulty element under warranty.

E. Installation-seam problems

The seam sealing comes away and gaps appear. Solution: remove the slopes, re-seal the seam with quality foam and a vapour barrier.
A stretched frame. If the frame was skewed or "stretched" during installation, the sashes may not sit tightly. Solution: refitting the frame (difficult and expensive) or an attempt to compensate by adjustment, though not always successful.
Errors fitting the strike plates. The plates are screwed in the wrong place or don't provide the necessary pressure. Solution: refit the strike plates.

F. Technological factors (design features)

A draught from the top hinge. This is often not a defect but a design feature: the seal is interrupted at the hinge. Usually it's a micro-draught that doesn't affect the overall temperature. Solution: if it bothers you, an additional seal or wind protection can be fitted.
A draught through the window handles. Rare and usually unnoticeable. Solution: replace the handle with a tighter one or seal it.
Seal deformation under blind/roller-blind fixings. Wrongly chosen fixings can press on the rubber. Solution: select correct fixings.
Poor air circulation behind long curtains. Warm air doesn't rise to the window. Solution: ensure free circulation (short curtains, ventilation grilles in the sill).

What to do if your window draughts

It can be hard to identify the cause yourself, especially if there are several. My advice: start with the simple — check the seal, try adjusting the pressure (the cams) and find exactly where the draught comes from (with a lighter or a damp hand). If that doesn't help, call a specialist. I carry out a full window diagnosis: I check the sash geometry, the condition of the seals, the operation of the hardware and the installation seams. After the diagnosis I give a precise recommendation and the cost of fixing it. The call-out and diagnosis are free.

Frequently asked questions

Why does a closed plastic window draught? There are many causes — from a worn seal to installation errors. A diagnosis is needed.

Does switching to winter mode help? Yes, if the problem is weak pressure. But it's no cure-all: if the seal is rock-hard or there are gaps, the mode won't save you.

How much does seal replacement cost? It depends on the sash perimeter and the type of seal. I name the exact price after a free inspection.

Why come to me

Free call-out and diagnosis. I'll check the windows and name the exact cost.
Honesty. I won't push unnecessary work.
Quality materials — proven seals, hardware and sealants.
Warranty up to a year on all work, with clean, tidy work afterwards.

Order a window-draught diagnosis in Minsk

Don't freeze and don't spend money heating the street. Call me right now for a free consultation and to book a convenient time. I work in Minsk and the Minsk district — promptly and with a quality guarantee.

📞 Phone: +375 (29) 135-50-50
🌐 Website: rpo.by
Brand: Spravnae Akenca