How to Replace a uPVC Window Seal

By Kim
Last updated 28th June 2021 - Reading time: 8 mins

Are you looking for information on how to replace a rubber seal on your uPVC windows? This article will guide you through everything you need to know about a uPVC window seal replacement job, including a step-by-step guide on how to complete the job and a list of all of the tools and materials you’ll need to get the job done.

how to replace a upvc window seal

What Tools Do I Need to Replace a Rubber Seal on a uPVC Window?

Below is a list of the tools you’ll need to replace a uPVC window seal:

  • Builder’s knife
  • Ladder (if working on upper floor windows)

What Safety Equipment Do I Need for a uPVC Window Seal Replacement?

You won’t necessarily need to worry about any safety equipment when it comes to resealing a uPVC window. However, you should always be cautious when using a builder’s knife.

If you are working on an upper floor window, you will need to use a ladder to access the window properly. You should always take care when working on a ladder and have someone else on hand to hold the ladder while you’re on it to ensure you remain safe throughout the duration of the job.

What Materials Do I Need to Replace a uPVC Window Seal?

Below is a list of the materials you’ll need to replace a rubber window seal:

  • UPVC window rubber seal
  • Silicone sealant

How to Prepare for uPVC Window Seal Replacement

One of the first things you’ll need to do when preparing to change the seals on your uPVC windows is to check the weather.

If you are working on more than one window, then it’s likely you’ll be outside for a while, and the last thing you want is a huge downpour of rain right in the middle of the job.

Plus, you’ll have to have the window open whilst you complete the job, and having large amounts of rainwater flowing into the house through an open window is never fun. Try to choose a day when there is little to no rain expected.

You will also need to remove the old seals from your windows before you can begin installing the new ones. To do this, simply pinch a part of the seal and start pulling it away from the window.

Most seals should come away quite easily. If you find that you’re struggling to pinch and pull it away, you can use a builder’s knife to pray part of it away until it can be gripped between your fingers. Then, you can pull the rest away.

How to Replace a Rubber Seal on a uPVC Window Yourself

Follow our step-by-step guide below on how to replace a uPVC window seal:

Step 1

The first step in replacing your uPVC window seals is to remove the old rubber seal from the window. You can do this by pinching part of the seal and pulling it away. It should pull away quite easily.

how to replace a upvc window seal step 1

If you find that you’re struggling to pull part of it away, use your builder’s knife to pry a section away from the window and then pull the rest away by hand.

Step 2

Once the old rubber seal has been removed, you will need to inspect the window frame for any obstructions. Sometimes you might find that there are some melted bits of uPVC in the corners.

how to replace a upvc window seal step 2

If so, you should chip away at these to remove them before installing your new seal, and they may prevent the window from completely sealing properly. You want to be sure that you can push your rubber seal into its slot around the window.

Step 3

Once you’re happy with the window frame state, you can then begin installing your rubber seal. Start in one corner and work your way along with the entire window frame. The rubber seal should simply push into place within the grooves of the frame.

how to replace a upvc window seal step 3

Step 4

Repeat the above step for all four sides of the window frame until the rubber seal completely fills all four sides of the grooves.

how to replace a upvc window seal step 4

Step 5

Once you’ve finished installing the seals, take a moment to inspect the corners as you may find that there is a small gap where the two parts of the seal join together.

how to replace a upvc window seal step 5

If that’s the case, simply apply a small amount of silicone sealant to these areas to completely seal them off. Make sure you wait for the sealant to completely dry before closing the window.

Types of uPVC Window Seal

There are several types of the rubber seal that can be used on a uPVC window. Below is a list of the most common types of uPVC window seal in the UK:

Bubble Gasket

A bubble gasket seal is curved on the top, giving it its name. This type of seal works by flattening as the window closes, creating a water-tight seal and keeping draughts out. This type of seal tends to be the most commonly used seal for uPVC windows and doors in the UK.

Flipper Gasket

A flipper gasket seal is designed with a small wedge on the top of the seal that flattens into the gap between the window and the frame when the window is closed. This creates an air-tight and waterproof seal. It’s seen as just as effective as the bubble gasket type of seal.

Bubble-Flip Gasket

This type of seal is simply a hybrid of the two seals listed above. It features a small wedge on top of a bubble shape. Some people prefer to use this hybrid option as it’s thought to provide even further protection, particularly against draughts.

The Benefits of Resealing uPVC Windows

There are several benefits to replacing the seals on your uPVC windows. Below is a list of the main advantages when it comes to completing this type of work.

  • Energy efficiency – Replacing the seals on your windows will increase the energy efficiency of your home. This means that you will save money on your energy bills, and your home will also be better for the planet.
  • Eliminate draughts – If your home is quite draughty, then it’s likely your windows and doors need to be resealed. Replacing the seal in your windows will make them air-tight and will prevent those pesky draughts.
  • Stops condensation – Condensation tends to form as a result of air passing through gaps in your windows. This can often lead to damp and mould and can leave your house feeling very cold. Replacing the seals on your windows can eliminate this problem.

FAQs

How do you remove the seal from uPVC windows?

You can remove your old uPVC window seal by simply pinching a part of the seal and pulling it away from the window. Most seals should come away quite easily. If you find that you’re struggling to pinch and pull it away, you can use a builder’s knife to pray part of it away until it can be gripped between your fingers. Then, you can pull the rest away.

How do I know if my uPVC windows need to be resealed?

You can look out several signs that will indicate you need new seals around your uPVC window. Below is a list of some of the most common signs that indicate you need new seals:

  • When you can feel a draught coming through the window
  • When you can see that there is wear and tear or damage on the seal
  • If you notice that the current seal has mould on it
  • If you start to notice condensation on your windows or windowsills
  • If it has been over five years since the seals were last replaced

How often should uPVC window seals be replaced?

It is recommended that you replace your window seals roughly every five years. However, if you start to notice any of the common signs that your windows need to be resealed as listed above, then you shouldn’t wait to get them resealed.

Do I need to hire a professional to seal my windows?

It is not usually necessary to hire a professional to seal your windows as it is quite a simple DIY job. However, you can hire a professional to complete the work for you if you would prefer not to do it yourself. The average cost that a professional will charge for resealing your uPVC windows is around £20-£40 per window. Each window seal replacement shouldn’t take more than an hour to complete.

How much does it cost to have my window seal removed?

In most cases, removing your window seal is quite a simple DIY job as it only really involves pinching the seal and pulling it away from the window. If you would prefer to have a professional remove your window seal, you would be looking at a cost of around £20-£50. This cost may vary depending on your location in the UK and the number of windows and doors that you would like the contractor to work on.

Sources

https://www.youtube.com/watch?v=HXzc4U85xPU
https://www.youtube.com/watch?v=gZn7a9ROS68
https://extrudaseal.wordpress.com/2015/06/19/a-simple-guide-to-replacing-glazing-seals

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