Fitting a Cat Flap in a UPVC Door

· 6 min read
Fitting a Cat Flap in a UPVC Door

Allowing your cat to go in and out of the house as it pleases is an excellent way to keep your pet physically active and mentally engaged. Having a flap can also aid in reducing toilet accidents by making it easier for your cat to exit the house when it is required to.

Take a measurement of the door

A cat flap lets your pet to move around at their own pace, without opening the door for them. This is a great way to keep your pet inside the home when you are away or at home. It also helps prevent unwanted pests from entering.

It is essential to measure the door before you buy the cat flap, as there are various sizes available. You should then make sure that the cat flap is the correct size for your upvc doors. Otherwise, it may be too large or small and your cat may be unable to use it.

Use a ruler to measure the width at several points along the edge of the door. Also, determine the door's height in a few spots. This is because the door that is too high could cause your cat to do an exercise routine like a gymnast every time they need to use the flap!

If you're not sure of how to measure the door, it could be a good idea to seek assistance from a glazier, or someone who does this type of work often. They'll be able to determine if your door is suitable for cat flaps and give you advice on the right size flap you should purchase.

After you've gotten your measurements, the next step to do is mark out the shape of the hole in the door. This will help you when you cut the hole and save you money!

Make sure to put the hole in the right position. For instance, if fitting the cat flap in the patio door, it's important that the hole is not too close to any hinges, since this could cause leakage and issues with the seal.

If you have a glass door, it might be best to leave this task to a professional glazier. It can be difficult to install a cat-flap in an existing pane. It is also possible that it cracks and loses its weatherproof seal.

Measure the Cat

A cat flap allows your pet to come and go whenever they want without you needing to leave him alone. It can also prevent draughts entering your home, which is not healthy for your cat or you.

If you own a uPVC door or composite, it might be difficult to install the cat flap. These kinds of doors are often made from different materials than traditional wooden or uPVC doors, and the installation process is different as well. Make sure to inquire with the manufacturer to see if it is compatible before installing a cat flap on your uPVC composite or uPVC door. Modifications can be detrimental to warranties.

These doors are generally designed to be durable and tough and have insulation. They are more resistant to weather than other kinds of doors, but it isn't always easy to install an animal flap. If you're uncertain about whether your uPVC or composite door can accommodate the cat flap, make sure you consult with a professional jointer prior to starting.


You'll have to measure their height to ensure they pass through the door. It is easiest to measure their height when they're calm or asleep, so they don't move around. Once you have their height and weight, you can determine the distance between their stomachs and the floor to determine the location of the flap's bottom. This position can be marked on the door.

If your uPVC or composite door is made from metal (either aluminium or steel) it is important be extra cautious when cutting it using power tools. Drilling into metal can cause it crack, especially when the area is made of toughened glass. It is highly recommended to hire a glass installer when installing an e-cat flap on the pane. This will prevent the glass from breaking and becoming brittle. A Glazier will also be capable of providing you with a circular cat flap hole that is less likely to break and is safer for your cat to use.

Cut the Hole

If not then you can create one yourself by using a piece of paper (tracing paper is the best choice). If it doesn't, you could create your own by using a thin piece of paper (tracing papers are ideal). After the shape has already been penciled in on the door, utilize your spirit level to make sure that it is horizontal. This will allow the cat flap to be properly seated in the opening and stop it from being able to slide open or close.

Then, use your jigsaw to cut out the pattern that is marked on the door. Make  cat flap installation  that you're using a blade that is suitable for use on uPVC doors - usually it will be marked as such If not, ask the staff at your DIY store for assistance. Once you have the hole made, place the flap section against it and then push it out to ensure that the flap's action is smooth. If it is bound at any point, you can use the filer or the rasp to correct this.

Verify that there aren't electric or gas pipes within the door you plan to cut into. The jigsaw may damage them. Similarly you should be aware of any handles or other door fixtures which will need to be removed in order to fit the cat flap. You should be cautious not to scratch them in the process.

Most people who install a cat flap on their own have the standard solid uPVC front door, meaning they won't have to deal with these problems. However, if your door is made from wood or has decorative panels that cannot be removed, it will add to the complexity of the task.

It is always advisable to seek assistance from an expert cat flap fitter for these kinds of jobs because it is crucial to get the job done correctly to avoid potential problems in the future. It is essential to do it right because doing it wrong can damage the door and void the warranty.

Fit the Flap

Once you've got your hole drilled, put the flap on to test whether it opens easily. If you spot any areas that stick or catch, file them down with a hand file or sandpaper until it is a perfect fit and opens with no issues. Be sure that the flap is aligned with the door.

If your tool doesn't have a template, you can make use of thin paper such as tracing or Acetate. Place the paper on the door, and draw a line to show the location where the flap is placed (this will serve as your cutting guide). Then using the pencil lines you've made on the door, draw four screw holes in each corner of the flap - these will be the screws you'll use to put it into the right position.

The majority of uPVC doors are strong and easy to cut. If your door is constructed of composite or GRP the process can be more difficult. If you are not familiar with this, it is recommended to consult a professional. They can also provide you with advice on whether or not your particular door is suitable for installation of a cat flap.

It is possible to install the cat flap onto composite doors, but it is important to check with the manufacturers or a professional joiner first since any modifications to these doors could invalidate the warranty. If you do decide to complete the task yourself, be aware that this can be a messy and potentially dangerous job.

You'll need to use a saw or grinder to cut through composite doors, rather than only the GRP. Be aware that this can be a very hazardous job and you'll need to take great care not to damage the door or yourself since it is extremely fragile. It's worth noting that it is much more difficult to create a hole in a door glass than a uPVC door or a solid wood door.