Understanding the Difference Between Wedge Gaskets and E Gaskets

When it comes to maintaining or improving the performance of your windows and doors, glazing gaskets are an important component that keeps your home warm and comfortable. These components might not get much attention, but they are essential in ensuring your windows stay secure, weatherproof and energy-efficient. Two common types of gaskets you might encounter are wedge gaskets and E gaskets. Although they operate in a very similar way, understanding the difference between these two gaskets will allow you to purchase the correct product for your home.

This article from Seals Direct examines what wedge and E gaskets are, how they function, and where they’re typically used.

What is a Glazing Gasket?

Before examining two different types of glazing gasket, it is important to understand the purpose of glazing gaskets in general. These rubber seals are used in windows and doors to either hold the glass securely in place or create a reliable seal when the window is closed against the frame. These seal, available in many different shapes and sizes, help prevent draughts, moisture and noise from entering your home. They can often help improve your thermal efficiency, reducing the amount you spend on keeping your home warm and comfortable.

Over time, these gaskets can perish and become less effective due to exposure to the elements, UV rays and temperature fluctuations. Replacing these seals when they begin to deteriorate is essential for maintaining the functionality of your windows and doors.

Selection of Glazing Gaksets

What is a Wedge Gasket?

A wedge gasket is a rubber seal designed to fit snugly into the gap between the glass pane and edge of the frame. Its primary function is to hold the glass securely in place by filling the gap and applying pressure against the window. This helps ensure that the window stays firmly seated in the frame and helps create a reliable watertight seal.

The term "wedge" comes from its unique wedge-like shape that allows for easy insertion into the gap it needs to fill. This helps create a strong grip between the glass and the frame. They are available in a large range of sizes, depending on the size of the gap they need to fill. This usually ranges from 1.5mm to 4mm on residential properties, but can be up to 8mm on larger industrial windows.

They’re commonly used in uPVC windows and doors, although they can also be found in some aluminium frames.

Wedge Gasket

What is an E Gasket?

An E gasket is another type of glazing gasket commonly used in glazing applications. It gets its name from its shape, which resembles the letter "E". This design includes multiple protrusions or "legs" that compress when the gasket is fitted to create a tight seal against the glass and the frame.

E gaskets serve a similar purpose to wedge gaskets as they hold the glass in place and provide a weatherproof barrier. However, their design includes an arrow foot that allows the profile to be pushed into a recess in the edge of the aluminium channel. This eliminates the requirement of holding the profile against the edge of the frame when assembling the window.

E gaskets are often used in modern uPVC and aluminium windows and doors. They’re particularly popular in double-glazed units, where their shape helps to accommodate slight variations in glass thickness.

E Gasket

Key Differences Between Wedge Gaskets and E Gaskets

The most noticeable difference between wedge gaskets and E gaskets lies in their shape and design. Wedge gaskets, as the name suggests, feature a tapered wedge-like profile. This shape is designed to grip the glass pane tightly to ensure it stays securely seated within the frame. On the other hand, E gaskets have a distinctive "E" shape with multiple legs that compress to create a tight but flexible seal. This design makes E gaskets especially effective at accommodating slight variations in the size or positioning of the glass.

Another difference is the location where each type of gasket is typically used. Wedge gaskets are most commonly found on the interior side of windows and doors. They serve to secure the glass firmly in place while also providing additional insulation. This compares to E gaskets that are often installed on the exterior side of the frame.

This highlights the unique difference in their primary function. Wedge gaskets are ideal for ensuring the glass is securely held to minimise significant movement or stress, such in high-wind areas. This differs to E gaskets that are excellent for sealing against external environmental factors. Their design makes them better suited for preventing water intrusion and handling the challenges of outdoor exposure.

The installation process also differs between these two types of gaskets. Wedge gaskets need to be firmly pressed along the top of the section to secure them within the gap between the glass and frame. They are typically fitted after the glass has been placed in the channel. E gaskets differ in that they are usually installed before the glass has been fitted into the channel. This is to allow enough space for the arrow foot on the section to be inserted into the recess in the side of the channel. They also naturally compress and adapt to the frame and glass which makes them a more forgiving option for those with less experience or when slight irregularities are present.

Which One Do You Need?

If you’re replacing glazing gaskets, the first step is to identify the type of gasket your windows currently use. You can do this by carefully removing a section of the old gasket and comparing its profile to the products on our website. Although these products serve a similar purpose, they do each have a unique shape that will allow you to identify the type of product you require.

We have also written a technical guide on how to Measure the Gap for Wedge Gaskets. This explains the process of measuring the gap between your glass and frame to help identify a replacement section.

For support or assistance when choosing a replacement glazing, door or window seal for your home, please get in touch with the technical team at Seals Direct. For further information on any of our products or for technical assistance in choosing the best replacement gasket, please get in touch with our knowledgeable team.

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