Window seals play an essential role in keeping your home warm, quiet, and energy efficient. Over time, however, these seals can wear out and lose their effectiveness, allowing draughts, moisture, and cold air to enter.
In this guide, we cover everything you need to know about uPVC window seals. What they are, how long they last, why they fail, and when to replace them to keep your windows performing at their best.
What Is a Window Seal?
A window seal, also known as a rubber gasket, is a flexible strip fitted around the edges of windows and doors. These seals are most commonly found in uPVC frames and are designed to create an airtight barrier that blocks out cold air, noise, and water.
There are a few main types of window seals:
• Bubble Gasket Seals: Installed around the opening of a window or door, these have a rounded bubble shape that compresses to form a tight seal when closed.
• Wedge Gasket Seals: Found around the glass unit, these create a secure fit between the glass and the frame.
• E-Gaskets: Used in certain uPVC systems, these also sit around the glass to hold it firmly in place.
Each type serves a slightly different purpose but all are designed to maintain insulation and comfort inside your home.
Can Window Seals Be Replaced?
Yes, window seals in uPVC windows and doors can be easily replaced. The process is straightforward and usually does not require any special tools.
In most cases, you can remove the old seal and press in the new one by hand. Replacing your window seals is one of the simplest and most cost-effective ways to improve your home’s insulation and energy efficiency.
What Causes Window Seals to Fail?
Window seals can fail for several reasons, most of which are related to age and environmental conditions.
1. Wear and Tear: Over many years, seals naturally flatten and lose their shape, reducing their ability to form a tight seal.
2. Shrinkage: Cold weather can cause rubber seals to contract, pulling them away from the corners of the frame.
3. Brittleness: Exposure to sunlight and temperature changes can make rubber seals dry out and crumble over time.
When these problems occur, your window seals will no longer prevent draughts or moisture, allowing cold air to seep in and warm air to escape.
How Long Do Window Seals Last?
Most window seals last for around ten years, and many window manufacturers offer a similar length warranty. However, it is good practice to inspect your seals every five years for signs of wear or damage.
If you notice cracks, flattening, or shrinkage, replacing the seals early can prevent heat loss and condensation issues later on.
Can Window Seals Be Repaired?
Unfortunately, once a window seal has lost its shape or become brittle, it cannot be repaired. Rubber that has deteriorated will not regain its flexibility or sealing ability.
The only effective solution is to replace the seal entirely with a new one. Fresh seals will restore insulation, eliminate draughts, and extend the life of your windows.
Do Windows with Broken Seals Need to Be Replaced?
You do not need to replace the entire window unit. Only the seals themselves.
If you notice your seals are no longer performing well, replacing them will immediately improve insulation and reduce energy waste. In many cases, homeowners see a noticeable difference in warmth and even a reduction in heating costs after fitting new seals.
How to Tell If Your Window Seal Has Failed
Checking whether your window seals are still effective is easy. Here are a few simple ways to test them:
1. Feel for Draughts: On a cool day, run your hand around the edges of the window. If you feel a cold breeze, the seal has likely flattened and is no longer airtight.
2. Inspect the Seal: Remove a small section and examine it. If the rubber looks squashed, cracked, or crumbly, it needs replacing.
3. Look for Shrinkage: Check the corners of your window. If you can see gaps where the seal has pulled away from the frame, it has shrunk and should be replaced.
These simple checks can help you identify problems early and prevent costly heat loss.
How to Stop Cold Air Coming Through Windows
The best way to stop cold air entering your home is to replace old or damaged window seals. If your seals are over ten years old, they will almost certainly need updating.
Replacing them will instantly improve insulation, reduce condensation, and help maintain a steady indoor temperature.
If you still experience draughts after replacing the seals, your window hinges may also be worn. Loose or bent hinges can prevent the sash from closing tightly against the seal. Replacing both the seals and the hinges together will give the best results for energy efficiency.
Window seals are a small but vital part of your home’s comfort and performance. Over time, they can deteriorate, allowing cold air and moisture to enter. But, replacement is quick, easy, and affordable.
By checking your seals regularly and replacing them when needed, you can maintain warmth, reduce energy bills, and extend the life of your uPVC windows.
At FixTrade.co.uk, we offer a complete range of bubble, wedge, and E-gasket window seals for all types of uPVC windows and doors. Browse our collection online and find the perfect seal to keep your home warm and draught-free all year round.