Fitting a Cat Flap in a UPVC Door

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

The ability of your cat to come and go out of the home at its own pace is a great idea to keep it physically and mentally active. Having a flap can also aid in reducing toilet accidents by making it easier for your cat to leave the house when it needs to.

Measure the Door

A cat flap lets your pet move around as they want without you having to open the door. This is a great way to keep your pet safe in the house when you're away or at home. It also helps prevent unwanted pests from getting into your.

It is essential to measure the door to ensure that you get the right size cat flap. There are many sizes available. You should then make sure that the cat flap is the correct size for the door you have. Otherwise, it could be too large or too small, and your cat could have difficulty using it.

Before you take any action but use a ruler to measure the width of the door in various places along its edge. You should also determine the door's height in a couple of places. This is because the door that is too high could cause your cat to do the gymnast's routine each time they want to use the flap!

Get help from a glazier when you're unsure of how to measure the door. They will be able to assist you in determining whether not your door is suitable for a cat flap and advise you on the right size of flap you should purchase.

Once you've got your measurements, the next thing to do is mark the shape of the hole in the door. This will assist you when you cut the hole and save you money!

Make sure to put the hole in the right location. If you are fitting an apex flap to the patio door, it is important that the hole doesn't reach too close to the hinges. This could lead to leakage or problems with the seal.

If you have glass doors it is best to delegate this task to a glazier. It can be difficult to install a cat-flap within an existing pane. You may also find that it cracks and loses its weatherproof seal.

Measure the Cat

A cat flap lets your pet come and go whenever they want without you having to leave him home on his own. It can also prevent draughts entering your home, which isn't healthy for your cat as well as you.

However, if you own a uPVC or composite door it may be difficult to install the cat flap. These doors are constructed of different materials, and the way they are installed is different. Make sure you check with the manufacturer if the door is compatible before you install an uPVC cat flap on your uPVC composite or uPVC door. Alterations may be detrimental to warranties.

These doors are typically designed to be durable and tough, with insulation. This makes them more resistant to the elements of weather than other types of doors, but they may be a challenge to insert the cat flap. If you're uncertain about whether your uPVC or composite door is able to accommodate a cat flap, consult with a professional joiner prior to beginning.

To ensure that your cat can access the door, you'll need to measure their height. This will be easiest if they are sleeping or calm, so that they're not moving around too often. Once you have their height you can measure the distance between their stomachs and the floor in order to determine the position of the bottom of the flap. You can then mark this spot on the door.

If you are using power tools to cut your composite or uPVC door, you have be extra cautious. The process of drilling into metal can cause cracks, particularly if the area is toughened glass. This is why it's highly recommended to engage an expert glazier to install your cat flap into the glass pane. This will prevent the glass from becoming fragile or shattering. A Glazier is also in a position to provide you with a cat flap that is less likely to break and is safer for your cat to use.

Cut the Hole

A good cat flap comes with a drawing template that you can use to mark the location on your door where the hole will go. If it doesn't, you could make your own using a thin sheet of paper (tracing papers are perfect). After the shape has already been drawn on the door, you can use your spirit level to make sure it's horizontal. This will allow the cat flap to properly fit into the opening and stop it from being capable of sliding open or closed.

Then, you can use your jigsaw and cut out the shape drawn on the door. Make sure that you are 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 advice. Once you have the hole cut out, place the flap section against it and then push it open to make sure that the flap's movement is smooth. If it binds on any point, then make use of a file or a rasp to fix it.

Make sure there aren't any electric or gas pipes in the door you plan to cut into. Your jigsaw could cause damage to them. Be aware of any handles or other fixtures that are in the door, which have to be removed to fit the cat flap. Be cautious not to damage these items in the process.

The majority of people who install a cat flap on their own have a standard solid uPVC front door, so they won't have to deal with these problems. If your door is made of timber or has an ornamental panel that can't be removed, this could increase the difficulty of the job.



It is always worth seeking professional assistance from a cat flap fitter when it comes to these types of jobs since it is crucial to get the job done correctly to avoid potential issues in the future. Getting it wrong can lead to the door being damaged, which could make it impossible to honor the warranty.

Fit the Flap

After you've cut your hole, place the flap to check if it opens and fits well. If you notice any spots that stick or catch, file them down with an sandpaper or hand file until it is a perfect fit and opens without issue. Make sure the flap is in a flush position with the door.

Some kits include a template for this however, even if yours does not provide a template, you could use a piece or thin paper instead - something like tracing paper ideally. Place the paper on the door, and draw a line to indicate the location where the flap is placed (this will serve as a cutting guide). Then, using the pencil lines you've drawn on the door, mark four screw holes in each corner of the flap. These will be the screws that you'll use to secure it in place.

Most uPVC doors are sturdy and easy to cut. If your door is constructed of composite or GRP, it can be more difficult. If you're not familiar with this, it might be advisable to hire a professional to do the job for you. They will also be able to help you determine whether or not your specific door is suitable for cat flap installation.

You can fit the cat flap onto composite doors, but it is important to check with the manufacturers or a professional joiner first as any alterations to these types of doors could invalidate the warranty. If you decide to complete the task yourself, remember that this could be a messy and potentially dangerous task.

You'll need a grinder or saw to cut through composite doors, rather than just the GRP. Be aware that this could be a very hazardous job and you'll need to take great care not to hurt the door or yourself as it is extremely fragile.  cat flap installers near me repairmywindowsanddoors.co.uk  noting that it's more difficult to make a hole in a door glass than a uPVC door or solid wood doors.