Checking and Adjusting Window Seal Compression in Minsk

When the cold weather arrives, many residents of Minsk and the Minsk district face the problem of draughty windows. The window seems tightly shut, yet cold draws in from somewhere. Most often the cause is insufficient or uneven pressure of the sash against the frame. In this article I — Dmitry, a window repair master with 20 years' experience — will explain how to check the pressure correctly, adjust it, and when you can't do without a specialist's help.

How to check a window's pressure

Many advise using a sheet of paper: clamp it with the sash and try to pull it out. But this method is ineffective. Even with ideal pressure the sheet can slip out, and with weak pressure it can be gripped. Paper gives no objective assessment. For a precise diagnosis I use other methods:

Visual seal inspection. A quality seal should compress by about 1 mm when the sash is closed. If it's flattened, cracked or, conversely, doesn't make contact, the problem is obvious.
Checking for light. A gap that lets light through is a clear sign of weak pressure.

The pressure should be sufficient (but excessive pressure on the seal leads to its rapid wear) and even around the whole perimeter of the sash (skews create local gaps and overload the hardware). Window makers usually recommend a working seal compression of about 1 mm. This ensures a tight seal and extends the life of the rubber.

Why plastic windows draught

There can be several causes:

Incorrect sash adjustment. If the sash is skewed, there will be a gap in one corner even at strong pressure.
Seal wear. The rubber loses its elasticity over time, cracks and flattens. This happens especially quickly on the sunny side.
Installation errors. Poorly foamed seams, no vapour barrier — the draught may come not from under the sash but from the installation seam.
Insufficient or incorrectly placed pressure cams. On sashes over 130 cm tall there should be at least three cams on the handle side, no further than 30 cm from the corners. On wide sashes (over 60 cm) pressure points at the top and bottom are desirable.

Adjusting the pressure: what you can do yourself

On the edge of the sash there are locking elements — cams (eccentrics). They can be turned to change the pressure. For the adjustment use pliers or a hex key (depending on the type of cam). Turn all the cams on the sash to the same position. Usually turning them about 90° is enough to switch from summer to winter mode.

Important: don't overdo it! Strong pressure wears out the seal and can make the handle hard to close. After adjusting, check the pressure. If the window closes easily and doesn't draught — you've done everything right.

The myth of winter and summer mode

It's often said that a quality window needs no seasonal adjustment. Indeed, if the window was correctly assembled from the start and the seal is elastic, you can do without switching. But in practice, especially in regions with cold winters, a slight increase in pressure for winter helps avoid draughts and reduce heat loss. The main thing is not to forget to ease it off in spring, so the rubber can rest.

When you need a master's help

Adjusting the cams doesn't always help. If the window still draughts after all the manipulations, the cause may be a worn seal, a sash misalignment or an installation defect. In that case I replace the seal (REHAU, KBE, Schlegel) or adjust the sash in all planes.

Frequently asked questions

How often should the window pressure be adjusted? Ideally twice a year: tighten a little in autumn, ease off in spring. But if the window doesn't draught, you can leave it alone.

Can a thicker seal be fitted to improve the pressure? No, that's a mistake. Too thick a seal creates excessive load on the hardware and handle, and they wear out quickly. You need a seal of exactly the same profile as the original.

Why does the handle close more stiffly after adjusting the cams? This is normal if you've increased the pressure. The main thing is that you can close the window without excessive effort. If the handle turns very stiffly, you've overdone it — ease it off a little.

How much does a master's call-out for setting the pressure cost? The call-out and diagnosis are free. You pay only for the work. If a simple adjustment is needed, the price will be nominal. I name the exact cost after an inspection.

Why come to me

20 years of experience. I know all the subtleties of adjusting windows from different makers.
Free call-out and diagnosis in Minsk and the Minsk district.
Quality materials and a warranty on all work.

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