Can you Have a Cat Flap in a Glass Door?


For many cat owners, it is important to be able to let their cats come and go as they please, without having to be home to open the front door for them. For this reason, the cat flap or cat door has become increasingly popular over the years. However, the installation of cat doors seems to have some limitations.

Can you install a cat flap in a glass door? Cat flaps can indeed be installed into glass doors, windows, French doors or sidelights. Fitting a cat flap within glass would usually require the make of a new piece of toughened glass with withstand the pressure of the cat flap. Most people get cat flaps put into a single glazing in a door. It is also possible to purchase premade glass doors with the cat flap already installed.

It is important to contact professionals to ensure the job is done correctly and that the structure of the glass door is not compromised.  Otherwise, you put both your door and your kitty in danger.

If you want to find the best Cat Door Insert, click here.

Can I Install the Cat Door Myself?

Unless your glass door already has a hole in the bottom, then no, you cannot cut a hole in your glass door and install the cat flap yourself.  You will need to contact a professional to create the hole in your glass door. This person is called a glazier. If your glass door is a slider or a window, it is likely to be tempered, and tempered glass can’t be cut. A glazier will measure your glass and simply order you a new one with the hole already cut into the glass, and then they will install the door for you.

Once you have acquired the new glass door piece with the hole in it, you do not technically need a professional to install the cat door. This part can be done yourself! However, if you’ve already got the expert out there cutting the hole, you may as well have them expertly and effortlessly install the cat door for you. Just sayin’.

How to Cut Glass Circle for Cat Flap, Using an Angle Grinder

If you are a professional handyman, but simply have not yet had the opportunity to cut a hole in the glass for a cat flap–here’s how to do so using an angle grinder. (We still recommend only skilled glass professionals perform such a task.)

An angle grinder can cut through thin laminated glass. It will not, however, cut through toughened glass or dual pane. For this project, we recommend you use the Super Thin 105mm (4”) Glass Cutting Diamond Blade.

Begin by tracing the size circle needed for your cat flap. Place a colored masking tape to make the lines of the circle more visible while cutting. Be sure to wear a face shield, earmuffs, dust mask, and cover your skin (since glass particles will be flying everywhere.) You will need a P2 or N95 rated mask at a minimum due to the glass dust particles, unless you want to breathe in Silica.

It will take anywhere between 10-15 minutes for the cut to be complete. Once the glass circle falls through, take a dry paintbrush and dust the glass particles away. Then clean the glass with a glass cleaner before then installing your desired cat flap/door.

This video shows how the angle blade saws through the glass.  You’ll see how complicated it is. And here’s another video that shows the finesse needed to cut a circle in glass.

Recommended Cat Flaps for Glass Doors

There are many cat flaps on the market today, so we’ve narrowed the playing field a bit by sharing our favorites:

Best Overall Cat Flap

Sure Flap Dual Scan Microchip Cat Door 

The Sure Flap cat door is the best on the market, in our opinion, because it prevents other critters from crawling through the flap and entering your home. This cat door has a selective entry technology (i.e., microchip reader) that allows you to program your cat’s unique microchip into the door so that only your cat can pass through the flap.  

It can store up to 32 different pet identities (a little excessive, but amazing), and it remembers all registered cats even when the batteries are removed. Speaking of batteries–it has a 12-month battery life and the batteries are traditional AA (easy to source and replace!).  This cat flap also contains manual locks which can determine whether the cat flap will open for your cat, via your command. If you want your cat to be allowed in, but not out, you can do that! Or vice versa.

The microchip reader works for all common ID microchips & RFID tags. Watch this video to understand just how cool and revolutionary this cat flip is.

Considering the scope of this technology, we think this cat door is also relatively cost-effective as well, priced less than $70.

Best Glass Door Insert

PetSafe Sliding Glass Cat Door Insert 

Most PetSafe products are awesome! This sliding glass door insert is no exception. We love that this cat door insert requires zero cutting or drilling what-so-ever, because the cat flap has already been pre-installed in the insert. It’s the perfect solution for pet parents who don’t own their own space but rather rent a home or apartment. Its design is ideal for a ‘temporary’ installation. Meaning, you can take the door with you when you move!

The frame is super sturdy and made from aluminum. And the glass is tempered and weather-resistant; it can withstand heavy use. PetSafe offers three different door sizes (ranging from small pets at 15 pounds, medium pets at 40 pounds, up to large pets at 100 pounds!)

The only negative is that the insert runs around $200. However, this is inexpensive if you consider how costly it is to hire a professional glazier!

Best Energy Efficient Cat Door

Endura Flap Vinyl Cat Door for Sliding Glass – Only $400 plus!

This energy-efficient design from Endura is an excellent cat door option. It is, however, rather expensive (we’re talking around $400.) However, the glass sliding door is made with dual-pane LoE glass and an award-winning pet door flap! The frame is made of strong vinyl and it securely fits into modern sliding glass door frame tracks.

The cat door flap is weather-resistant, capable of withstanding and resisting up to 50mph winds and keeps any rain or snow out. This Endura flap is also so easy to both install and remove (making it an ideal choice for renters.)

Best for Price

CEESC Large Cat Door for Windows & Sliding Glass Door  

This glass door is not only totally functional but completely affordable! This cat flap costs around $20 and is simple and easy to install. The door comes with the transparent flap (so you can see your kitty), the waterproofing exterior seal, and a brush strip that eliminates noise when the flap opens and closes. 

This cat flap is by far the easiest to install and is made of high-quality materials (ABS material, weather-resistant, and durable and smooth surfaces.) Additionally, this cat door has a 4-way-switch mode., which can be adjusted to: both in and out, out only, in only, or fully locked.

The Key Takeaway? 

If the only thing that’s been preventing you from installing a cat flap for your adventurous feline is the fact that you have a glass door, then fear no more! We hope this article is the encouragement you needed to call that local glazier and get your glass door measured and ready for your new cat door!

Unfortunately, cutting a hole in a glass door is a difficult D.I.Y project and does require the assistance of a skilled professional in the glass trade. Any local and highly rated glazier will be able to measure and create a new glass panel with the correct sized hole to accommodate your cat door. 

Related Questions

  1. Can you put a cat door on double glazing? Cat doors can be installed into doors and windows that are double glazed. It is not as simple as cutting into the glass. A new glazing unit would need to be made.
  2. Does a cat flap affect home insurance? Cat flaps do cause issues with home insurance claims. It shows negligence to protect the home since there is an opening to the home.
  3. Can rats come through Cat Flaps? Rats can come through cat flaps by jumping and gnawing through them. It is important to put your cat flap at a minimum of 6 inches off the ground to make it harder for rats to jump through.

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