Caring for Plastic Window Seals — How to Extend the Life of the Rubber

When we have new plastic windows fitted, we count on many years of trouble-free service. But sometimes, after just 1–2 years, the first warning signs appear: noise comes in from the street, dust settles on the slopes, and in winter you start to feel a noticeable draught. On closer inspection it turns out the seal has flattened, dried out or slipped at the corners. Sound familiar? By this point the warranty has most likely already run out. Unfortunately, only a few window owners know that the seal needs regular care, and even fewer do it correctly. In this article I — Dmitry, a window repair master in Minsk (Spravnae Akenca) — will explain how to extend the life of the rubber seal and avoid a premature replacement.

Why the seal goes bad quickly

The main enemies of rubber are dust, dirt, temperature swings and ultraviolet light. Over time the factory-applied lubricant dries out and the seal starts to "work dry". It hardens, loses elasticity and cracks — and then the draughts begin.

How to care for the seal: a step-by-step guide

The care procedure is simple and takes no more than 20–30 minutes for all the windows in a flat. It's enough to do it once a year, ideally in spring, after washing the windows.

Step 1. Cleaning. Thoroughly wash the seal with a soft, damp cloth. If you have a lip seal (the most common type), be sure to look under the lip — that's where most of the dirt collects. Remove all the soiling, especially at the bottom of the sash.

Step 2. Drying. Wipe the rubber dry with a clean cloth. There should be no moisture — this is important for the next stage.

Step 3. Applying a protective lubricant. Never use: vaseline, glycerine, vegetable or machine oils, WD-40. They either dry out the rubber or cause it to swell and break down. The ideal option is a silicone lubricant for rubber seals. You can buy it in any car shop or the household section of a supermarket. It's better to choose the liquid form (in a bottle) rather than a spray — it's easier to control the application. Apply a little, distribute it along the seal, and let it absorb. After that you can close the window.

What regular care gives you

The seal stays soft and elastic for up to 10–15 years.
The window closes tightly, ruling out draughts.
Sound and heat insulation are preserved.
You save on a premature replacement of the rubber.

Frequently asked questions

Can an old seal be restored? If the rubber has already lost its elasticity, cracked or flattened, care won't help — it needs replacing. But if you started caring for it in time, the seal will serve for years.

How often should the treatment be done? Once a year is enough. The best time is spring, after winter.

Where can I buy silicone lubricant? In any car shop or the household sections of hypermarkets. Look for products for caring for rubber seals — they're inexpensive and economical.

What if I don't want to do it myself? You can always order professional window servicing. I'll come, clean, lubricate and check the condition of all the seals. It takes a little time, and you'll be sure of the result.

Want your windows to last a long time?

Start with simple care. If you need help with diagnostics or a seal replacement, get in touch. I, Dmitry, a window repair master in Minsk, am always ready to help.

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