Fitting a Cat Flap

· 6 min read
Fitting a Cat Flap

Installing a cat flap into your home could be a major step for any pet owner. Whether your cat is old and requires extra security, or you have new kittens that require a thorough screening, there are plenty of options there for you.

It can be a bit daunting for non-professionals to install the cat flap, but with the proper guidelines, it's easy. The crucial factor is preparation, planning and accuracy.

Select the Right Door or Window

There are many different types of cat flaps, some with locks that can be used to stop your pet from leaving or in and others with advanced features like microchips for door entry systems. But, it's important to think about how easy your cat is to train to use the flap before you purchase and fit one.

Based on the style of your house, it's usually best to put the cat flap near the form of a door or window that opens to an area that is protected from the garden so that your cat is secure when entering and leaving the home. If you can it will also provide them a route back in should they be chased by a cat or by humans intent to harm them.

It's possible to put a cat-flap in a uPVC or composite door, but it isn't as easy as putting one in a wood door. This is because uPVC and composite doors are available in various thicknesses, which can affect how holes are cut and the material you're fixing it into.

If you're installing the flap on the glass of a door, it's recommended that you find a glazier who is experienced in this type of work to avoid costly mistakes. If you're fitting the flap on a wooden door, start by introduction of your cat to it before you fit it so that they can become familiar with its shape and size and explore it from all angles.

Take a look at your cat's belly measurement

You'll need the measurements of your cat to ensure that the cat flap you put in is a perfect fit. This will enable you to ensure that the cat flap is placed at the right height on the door or window, and that it is large enough to allow him to enter and out easily.

To do this, lay your pet on their back and run your fingers gently along their belly. Look for a fat pad that is squishy around the lower back and face, as well as the legs. The extra padding shields your pet and allows it to move more freely, particularly when performing feline acrobatics.

You can also use the weight of your pet to determine how large opening you require. If your cat weighs 5kg, for instance the suggested flap size is 14x12cm.

Measure Your Door or Window

This kind of cat flap, as the name suggests, is designed to be installed into a door. It allows your pet to enter and exit at its convenience. They are usually made from aluminum or plastic and sit in the centre of the door with a two-way swinging door that is opened by pushing lightly on either side. These flaps are available in locking versions that provide additional security so that your cat is not able to walk through the door from outside.

Cat flaps are also often used in windows. They are easy to be installed, but they have to be set at an elevated level since cats and dogs have a difficult time to reach them. If the window is too high for a cat flap, steps, ramps or purpose built stairs can be utilized to aid the animal in accessing it.

Cat flaps can be installed into a brick wall but this is not recommended unless you're skilled in masonry work as it could weaken the wall's structure. Before you begin, it is important to make sure that the wall is free of cables and pipes. It is recommended to consult a professional if you need to make a hole for pipes or cables. It is also recommended to wear protective goggles and a dust-proof mask to avoid inhaling any of the sawdust created by cutting into the walls of your house.

Select the Right Cat Flap

There are many cat flaps available on the market, and they all offer different features. Some are equipped with security features such as magnetic locks or microchip recognition to prevent unauthorized entry and also prevent your pet from allowing pets or friends into the house. Some have insulation as well as weatherproof seals that keep out the elements of moisture and draughts.

There are different sizes to choose from based on the size and breed of your pet. Cat flaps can be found in rectangular shapes, while others are square or circular. The kind of cat flap you select will depend on the size of the opening and the type of window or door you're fitting it to.

Finally consider the opening mechanism that your cat flap will come with. A simple aluminum or plastic swing-out door is one option and is usually the cheapest. However, it will not prevent other cats or pets from gaining access and you could let draughts through as well.


Once you have selected the right cat flap and measured your door or window, it's time to fit it. Determine the belly height of the door with your ruler. Make use of a spirit-level to ensure that the line is not too low and is in line with the door. Create a template for the shape of the cat flap using your spirit level as a guide. Then, you can use your saw to cut out the door's outline. When you are satisfied with the result then sand the edges and drill through the pencil markings to make holes for screws.

Prepare the Tools

It's important to have the right tools for doing any DIY project. The main things you'll need are the cat flap itself, a tape measure and a decent pencil and a spirit level drill, file and the jigsaw (depending on your window or door type).

Consult the manufacturer before making any modifications to a composite door. This could invalidate the warranty, or cause the weathertight seal to be damaged. In this scenario, it's likely that you'll need to replace the glass with a new piece of toughened glass.

You'll require an jigsaw for cutting out your cat flap on a wooden or uPVC door. Follow the guidelines given by the manufacturer. If possible, you can use an example to determine the dimensions of the hole you'll will need to cut.

After you have cut the hole, you will need to sand the edges of the opening. This will prevent any water damage or rust from occurring in the future. You should also cover the holes in your door or window and the side of the flap to prevent wind and rain. Once the sealant is dry, you're ready to install your new cat flap!

Install the Flap

If you want your cat to be able to move around as it pleases, fitting flaps can aid. Most people can put in the flap on their own. However when you plan to put it in glass or uPVC type door, you might need an expert.

Look at the instructions included with the cat flap. There is an illustration of the template.  replacement upvc door panels with cat flap Repair My Windows And Doors  will provide you with an idea of where the holes for the flap need to be made in the door. Mark the areas in which you will have to drill using the pencil.

After you've marked the door's area, use a jigsaw to cut out the shape of the cat flap. This is a fairly simple task however you'll need be comfortable with a Jigsaw. Many companies will complete this for you at a reasonable cost in case you're hesitant to tackle it yourself.

Then, you can screw the inside part of the door to the hole in your door. It may be necessary to seal the flap prior to you do this, in order to keep it weatherproof and watertight. Then, you can put the outer portion of the cat flap on the top of the fixing bolts and then tighten them all together. You should test the cat flap on your cat to confirm that it's working properly and allows them to enter and exit easily.