A window is made up of more than just glass and a frame — the seal is just as important. On uPVC windows, the seal (or window gasket) creates an airtight and watertight barrier between the glass and the frame. Without it, draughts, leaks, and condensation can quickly become a problem.
The Benefits of uPVC Window Seals
A well-fitted window seal keeps warm air inside and cold air out, saving money on rising energy bills. Even homes with double glazing can suffer from draughts if the seal has failed. Beyond energy efficiency, seals also reduce outside noise, keep pollen and dust at bay, and extend the life of your windows.
In winter, a damaged seal can allow moisture into your frames, which over time encourages black mould — a health risk linked to allergies and asthma. In summer, poor seals allow pollen and allergens to filter indoors. Replacing seals when needed is the simplest way to keep your home healthier, warmer, and more comfortable.
Types of Window Seals
There are several kinds of window gaskets, each suited to different applications:
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Bubble gaskets – flexible seals commonly used in uPVC frames to block draughts and leaks.
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Wedge gaskets – pushed into the gap between glass and frame for a tight, secure fit.
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E gaskets – widely used in uPVC windows to ensure a reliable seal between frame and glass.
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Groove or self-adhesive seals – fitted into existing grooves or stuck in place for quick installation.
Silicone sealants are also a popular option thanks to their durability, UV stability, and resistance to temperature changes, making them ideal for sealing around windows, bathrooms, and kitchens.
Signs You Need to Replace Your Window Seal
Window seals don’t last forever. Watch for these common signs of failure:
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Fogging between panes – unlike surface condensation, moisture trapped inside double glazing usually means the seal is broken.
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Damp or damaged frames – mould, bubbled paint, or warped wood suggest water is seeping past the gasket.
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Cold spots and draughts – if you notice fluctuating temperatures indoors, your seal may not be airtight.
Replacing seals promptly avoids wasted heating costs and prevents long-term damage to your windows.
Achieving the Perfect Finish
Replacing seals is only half the job — finishing them properly ensures long-lasting results. At GGR Glass, we supply a full range of sealant finishing tools to help you achieve a smooth, professional finish every time:
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Mastic Sealant Finisher – ideal for adhesive-based mastics on window frames and countertops.
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Angular Sealant Finisher – flexible and lightweight, perfect for sealing awkward corners and edges.
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Sealant Jointing Tool – designed for flush, tidy joints, with the option to mount on a pole for hard-to-reach areas.
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Sealant Finisher Tool Set – four different shaped tools in one compact set, suitable for a wide variety of sealant jobs.
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Glazing Tool Kit with Bag – a complete solution including scrapers, finishing tools, and accessories in one easy-to-carry kit.
GGR Glass
At GGR Glass, we know how important well-sealed windows are for comfort, efficiency, and safety. That’s why we stock a full range of sealant finishing tools to make sure your replacement seals are fitted correctly and finished to a professional standard.
Explore our full collection online, or contact our team for expert advice on choosing the right tools for your next glazing project.