Introduce your cat to the flap prior to when it's set up so they can get used to the size and shape. Open the flap and let your cat explore it from every angle.

Make sure that the cut-out is even and ensure that the cut-out is square and even. Mark the screw holes on your door and align them with the cat flap opening - the distance between the edges must be equal.
Preparation
Installing a cat-proof flap in your home is beneficial to the health and well-being of your pet. This is because it allows the pet to move freely between the indoors and outdoors without you having to let them in or out. It will also stop them from fighting over cat food, litter boxes or the door to the home.
The first thing that you will need to do prior to starting the installation of your cat flap is to prepare the area where it will be placed. This is because eliminating any obstructions from the area will make it easier to work. You will also want to take away any furniture or other decorations that could hinder the installation.
When preparing the area, you will need to take measurements and mark the location where you are planning to install the cat flap. This will stop you from making a mistake which could damage your wall or door. It is best to put the flap in a place that is easily accessible for your cat, yet doesn't harm the strength of the structure of your home.
A good location to place the cat flap is in a door that leads to an enclosed space, like your closet or laundry room. This will prevent your cat from jumping over it, and you can protect your pets from potential dangers. The cat flap should be low enough for your smallest cat to use, as taller cats may struggle to leap through a flap that is higher.
If you have an open patio door that slides or an old-fashioned sash window, it might be a good idea to employ an expert handyman for the task. It isn't easy to install the cat flap on these windows and doors and any mistakes can cause costly damage. A professional can install the cat flap without damaging the structure of the window or door's strength.
You will need to measure the height of your cat's belly from the ground to determine the flap's location. This will allow you to accurately cut out the opening for the cat flap. Once you have the line drawn with a spirit-level, use it to make sure it is completely horizontal. Next, check the instructions included in the cat flap kit to locate the template drawing. Attach the template to the door so that the bottom edge of the template is with the horizontal lines you have drawn. The template should be aligned in the middle of your door.
Measurement
A cat flap, sometimes referred to as a pet door is a small opening in the bottom of your exterior doors or windows that allow pets to enter and leave the house. They come in different sizes and materials, so you can choose the best one for your home and pets.
Before you buy a cat flap, it is important to accurately measure the dimensions of your windows or doors in which you're planning to put it. This way you can ensure that the hole to be of the correct size and that the cat flap will fit. This method can be used to determine the width of the opening by cutting off a section of it and walking through it with your pet.
It is also recommended to measure the height of your cat from the floor to the bottom on their belly. This will ensure the flap is placed at a height where your cats feel at ease. If it is too low, they could struggle to pass through. If it is too high, they might not be in a position to use the flap.
In general, you should aim to drill your holes at an angle of 45 degrees to the vertical surface. This will give the most secure and stable fixings for the installation of your cat flap. Ideally you should use a spirit level to aid you in this, but if the directions that came with your kit for installing a cat flap don't include this feature, a straight edge will do just as well.
When putting the cat flap onto a glass or UPVC window or door, it is best to employ an expert glazier to do this for you. This is due to the fact that these types of doors are normally made of toughened glass and drilling into them could weaken the integrity of the glass and possibly result in it breaking in the future which could pose a security risk for your home.
Placing a cat flap in a brick wall can be problematic too, as drilling into a soft area of the wall this can cause problems with cables and pipes that run through the property. This could result in costly repairs, or even leaks and weather damage caused by the outside.
Marking
After you've measured your cat or kitten to determine the correct size flap for them then you need to mark where the hole needs to go. Mark the center of the flap using a spirit level. If the template you've chosen for your cat flap kit doesn't include the centre line, copy it and draw around it with pencil to mark the spot where the hole will need to be cut.
Be aware that if the cat flap is too low, it will be difficult for your cat to go in and out of the house, and if the flap is too high, they might struggle to see what's happening outside. It is recommended to get it as close to your cat's belly as you can to give them the most comfort and security.
It is important to not place a cat flap too close to a wall frame. This could result in problems with draughts and damp. It's a good idea to seek help from a professional if you aren't familiar with masonry.
Next then, open the door and encourage your cat or kitten to enter it by showing them where to go (it is helpful if someone else is on the inside to help them). Once they've made their way through it, you can slowly start to allow them to enter and exit at will.
It is important not to force your cat or kitten through the flap too quickly as this can lead to them becoming scared. They could easily be injured by the clunk or snap when the flap closes, and even more scared if their tail gets caught in it when they attempt to get out. Cats are also known to return home to look for intruders. Leaving the door open can be dangerous. Your cat could be attacked by a cat they are familiar with. This is why it's recommended to install an uninspiring cat flap and only if your cat is aware of its use.
Installation
It is important to show your cat how to use the flap once it's installed. It will take some time, but with patience, and a few treats as motivation, your cat will eventually learn how to use it. Install a lock to the cat flap if you want extra security, particularly during bad weather or when you're away from home.
Decide where you'd like to put the cat flap on your door. It should be placed in a spot that can open up to an area that is protected from the elements of your garden. This will make your cat feel secure as they enter and exit the house. It can keep other animals from entering your home.
It is also important to take into consideration the height of the flap. This should be in accordance with the measurement of your cat's stomach to ensure that they are able to traverse through. You can also place steps either side of the entrance to assist your cat pass through.
Once you've decided where you want to place the cat flap You can measure the door with a pencil and mark the spot. This will provide you with an idea of where to cut. Then, how much to install a cat flap 'll need to cut out an area on the door with a jigsaw. It is recommended to wear safety glasses and a dust mask while working on this, as breathing in dust could be harmful to your health. Once the square is cut and trimmed, you must sand the edges of the door to smooth the edges.
Once you have finished sanding, you can now replace the cat flap inside your door. The cat flap should be placed so that the lock, if there's one, is located on the inside of the door. Drill the screw holes if there are any on the door. Then carefully insert the cat flap in the hole. Make sure it fits perfectly.