Fitting a Cat Flap

· 6 min read
Fitting a Cat Flap

The process of installing a cat flap may appear daunting but it's simple by following the correct instructions. First, decide how high you want the cat flap to be (on average, belly height). Note this on your door and use the template included to help you drill.

If you have a kitten that is still a newborn, gently prop the door slightly open and invite it to walk through. Reward it as it passes through.

Take a measurement of the door

A cat flap is a great way to allow your pet to come and go in and out of your home whenever it wants. This will help keep your cat healthy by ensuring that it gets exercise as well as being able to get back inside if left outside in bad weather, especially during the winter. This will reduce the amount of time you allow your cat out or in, and keep your home safer by letting you know when it's gone.

However, it is important that the cat flap is fitted correctly to prevent your pet from escaping through it or be pushed through by any other animals (e.g. dogs). It is important to measure the height of your pet's stomach and the size of the doorway in your home to ensure the flap is at the right height. If your cat is longer or taller than the average, you can adjust the flap's height by moving it upwards or downwards by a small amount.

The next step is to use a spirit level to mark the center of the door. This is where you will put in the flap. Then, using the marks as an indication, cut out the shape of your flap with a Jigsaw. After cutting the flap then sand the edges to create smooth surfaces. Drill any holes you need to.

The process of installing the cat flap isn't as difficult as you believe and it shouldn't take more than two hours for the entire job from start to finish. However, the process can be a little more complicated if you need to fit it into the frame of a uPVC or composite door as these doors come in an array of thicknesses which can affect how the holes are cut and what they are inserted into. This is the reason we recommend hiring a professional to carry out the job, particularly if you have never worked with glass before.

Measure Your Cat

You will not have to spend hours of listening to the pet's meow to be let in or out. This is particularly useful if you are at work most of the day and your cat is in the house waiting for you to get home in any weather.

It is important to measure your cat first before you attempt the installation. While it may seem an easy task, it is important to make sure you measure correctly or your pet will find it very difficult to use.


Firstly, make sure your cat is calm and not stressed before you take the measurements. You'll need to keep them in a manner that they cannot move and ensure that the measuring tape or ruler is flat against their body, not bending in any place. Holding the measuring tape or ruler against their body from the top of their head to the base of their tail will allow you to determine an exact measurement.

Once you've got the measurement of your cat, it is time to take a look at the door and decide on where you want to place the flap. Position the flap at the level of your cat's belly. This will allow them to pass through the door with minimal effort. This will also stop the flap from making a lot of noise when it swings back and back.

You should also think about the thickness and the structure of the uPVC door or composite. While timber doors are all of the same thickness, uPVC and composite doors can be very different in their overall construction and this can make the installation of a cat flap more complicated because you must ensure that the hole you cut is the right size for your pet.

It is also worth studying the instructions that come with the kit to find an outline of the template that can be used to mark out the location of the hole inside the door. This will enable you to determine where the hole must be located and ensure that the template is placed correctly on the door. Using a spirit level to make sure that the template is flush against the door will also be very helpful.

Cut the Flap

Before you can put in your cat flap, you'll have to cut the door's panel to make it large enough for it. It can be a difficult job, so it's recommended that you engage a professional to assist you if you don't have the knowledge or skills. You can also refer to the instructions included with the kit to discover how to do it properly.

You can take the height of the cat's or kitten's stomach to guide you. In general put the flap about 10-15 centimeters above the ground. This is the typical height of the belly for cats. This will allow your cat to move through the flap with ease and will make it difficult for other cats or nosy neighbors to get in or out.

Mark the position of the cat flap on the door with the pencil. Then, if your kit has an outline of paper, place this over the door and use the marks to drill holes in each corner of the template. Then, you'll be able cut out the template and replace it with the flap for cats.

You can put in your cat flap yourself inside the door made of wood or uPVC if you are confident with the use of a Jigsaw. Be sure to not cut through any of the door mullions or vertical rails. You can use a jigsaw to cut your panel into a square or a circle, depending on how you'd like to cut it. Take your time and don't force the jigsaw into cutting faster.

Once the hole is made, carefully place the cat flap in its new home. Make sure it is firmly secured. If the flap is fitted with screw caps, push them onto the protruding bolts. Once the screws are in place, sand any rough edges of the cut and then seal any gaps to ensure there aren't any draughts entering into your home.

Fit the Flap

If you have a basic cat flap, you can open it and encourage your pet to use it by placing a small amount of cat food in the front of the door. Alternatively you can try pushing the cat through with your hands or with a stick. Once your cat is used to moving through the flap, it is likely to be able in and out as it wishes so you can let it out or in without having to be there to open the door to allow it in all day (and likely in any weather).

You can fit an animal flap inside a UPVC or glass door although this may not be as simple as fitting one into a timber external door because the UPVC doors and some glass doors aren't a uniform thickness. This can have a significant impact on how you cut the opening for the flap and could affect the way your flap is fitted correctly after it has been put in place.

The mounting kit may include a template showing you where to drill holes. If the kit doesn't include a template you can make one on your own. When cutting, it is important to not push the jigsaw to the point that you create a bigger hole than necessary in your door.

Some cat flaps come in circular shapes, which are more difficult to put in. If you have a circular flap it is essential to ensure that the hole is in the proper location on your door as in the event that it's not, the cat will not be able to use the flap and could be stranded outside all day (or even night).

Certain models of cat flaps come with locks that permit you to control the time your cat comes and goes.  cat flap fitters repairmywindowsanddoors  are helpful when your cat is scared of going out in the dark, or coming back to the house at night. They can also be helpful when you are working all day. The lock can be used to allow or deny entry, and some can be locked in either direction allowing you to shut the door completely. This is especially helpful for sick or elderly cats who aren't willing to go out in rainy weather.