Fitting a Cat Flap Getting a cat flap fitted into your home could be a huge 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 difficult for people who aren't experts in installing an animal flap, but with right instructions it's easy. The most important thing is planning, preparation and accuracy.

Select the Right Door or Window

There are a variety of cat flaps, including some with locks that can be used to prevent your pet from leaving or in and others with advanced features like microchips for door entry systems. Repair My Windows And Doors UK to think about how easy it will be to train your cat to use the flap before you buy and install one.

Depending on the style of your home It is recommended to put the cat flap in an opening or window that opens to a sheltered area of the garden, so that your cat will feel secure entering and leaving the home. This will also allow them to return inside in the event of being chased by another animal or human beings who wish to harm them.

You can install a cat flap in the case of a uPVC door or glass window however, it's not as easy as putting one in wooden doors. This is due to the fact that uPVC and composite doors come in different thicknesses, which affect the way holes are cut and the materials you're fixing them to.

If you're installing the flap in glass doors it is recommended that you find a glazier who is experienced in this type of work to avoid any costly errors. If you are fitting the flap to the door made of wood it is recommended that you introduce your cat to it first so that it can become familiar with its dimensions and shape.

Measure Your Cat's Belly

You'll need your cat's measurements to make sure that the cat flap you choose to install is the perfect fit. This will help you ensure that the flap is the right height for your window or door and that it's large enough to allow them to enter and exit with ease.

To do this, lay your pet on their back and run your fingers gently across their belly. Feel for any squishy fat pads which might be visible around their lower back, face and legs. The extra padding protects your pet and allows it to move more freely, particularly when performing feline circus skills.

You can also use your pet's weight to gauge how big an opening you require. If your cat weighs more than 5Kg, for example the suggested flap size is 14x12cm.

Take a measurement of your door or window

This type of cat flap, as its name suggests is designed to be installed into a door. It lets your pet enter and exit at its convenience. They are typically made of plastic or aluminium and simply rest in the middle of the door. They have a two-way swinging door that is opened by pressing lightly on either side. There are locking versions of these flaps, which provide added security so your cat isn't able to traverse through the door from outside.

A window is another popular location for a cat's flap and these are easy enough to put in, but they usually need to be placed high up as it's difficult for dogs and cats to reach them otherwise. If the window isn't sufficient in height to be used as the flap for cats, you can opt for ramps, steps or stairs that are specially designed to aid the animal in getting to it.

A cat flap can be incorporated to a brick wall, but it is not recommended unless you're familiar with masonry work since it could weaken the structure of the wall. It is essential to ensure that there aren't any cables or pipes inside the wall before you begin. If they are, there must be a hole made for them. This is something that you should always seek professional advice on. Wearing safety goggles or a dust mask will help you avoid inhaling the dust that is generated when you cut into your walls.

Select the Right Cat Flap

There are a variety of cat flaps available on the market, and have different features. Some cat flaps have security features such as magnetic locks or microchips that prevent unauthorized entry. They also keep your pet from letting friends or other animals into the house. Some have insulation as well as weatherproof seals to keep out the elements of moisture and draughts.

There are also different sizes available depending on the size and breed of your pet. Certain cat flaps are available in rectangular shapes, whereas others are circular or square. Choosing the right type of cat flap will be dictated by the space you have available and the type of door or window you want to attach it to.

Lastly think about the mechanism for opening your cat flap is likely to have. A simple plastic or aluminium swing-out door is a good alternative and is usually the least expensive. However, it won't stop other pets or cats from gaining access and you could be letting draughts in too.

Once you have selected the appropriate cat flap and measured the windows or doors and window, it's now time to put it in place it. Begin by marking the height of the belly on the door using your ruler. Make use of a spirit-level to make sure the line isn't too low and is in line with the door. Draw a template of the shape of the cat flap using your spirit level as a reference. Then, using the jigsaw, cut out the outline of the door. When you are satisfied with the result then sand the edges and drill through the pencil marks to make holes for screws.

Make sure you have the tools ready

Like any DIY tasks, it's advisable to make sure you have the proper tools to complete the task. The most essential things you'll need are the cat flap along with a tape measure, an excellent pencil, a spirit level, drill, file, and a Jigsaw (depending on your door or window type).

If you're installing in a composite door, consult with the manufacturer before making any changes since this could cause the warranty to be invalidated or break the weathertight seal. In this instance you'll have to install an entirely new pane of toughened glass instead.


You'll need to use the jigsaw to cut your cat flap on wooden or uPVC door. Follow the directions provided by the manufacture. If possible, use an outline to help determine the size of the hole you'll will need to cut.

After you've made the hole, you must sand down the edges of the opening to smooth them. This will stop any rust or water damage from happening in the near future. In the end, you must apply any necessary sealant to the back of the cat flap and to the holes in the window or door to block the elements of wind and rain. Once the sealant has dried then you can put up your new cat-flap!

Install the Flap

If you want your cat to come and go whenever it wants, installing a flap can help. It's a simple procedure that most people can do on their own, but you'll likely require the help of a professional if you are installing the flap in an unglazed door or any other kind of uPVC door.

Check out the directions included with the cat flap. You will find an illustration of the template. This will give an idea of the location where the holes will be drilled for the flap to be placed in the door. Then, mark the places where you must drill using the pencil.

After you have mapped out the area in your door, use a jigsaw to cut out the design of the cat flap. This is a relatively simple task however, you'll need to be comfortable using a jigsaw. Many companies will do this for you for a reasonable price in case you're hesitant to take on the task yourself.

The next step is to attach the interior part of the flap onto the door's hole. You may need to seal it prior to making this move to ensure it is weather and water resistant. The outside of your cat flap could be placed on top of the bolts, and then securing them. It is recommended to test the cat flap with your cat to make sure that it works correctly and that they are able to get in and out of it.