Installing a Cat Flap into Glass and UPVC Doors

Installing a cat flap often makes life easier. These handy openings allow your cat, or dog, the freedom to come and go as they like. It means you don’t have to worry if you’re at work and a completely unexpected typhoon blows through town. Your pet can get safely inside where it’s warm and dry. But what if your door is glass? Can you install a cat flap into glass doors or panes?

Cat flaps help your pet feel more relaxed, more in control. But often houses aren’t built with the ease of a family pet’s access in mind.

The good news is that cat flaps can be installed into double glazed doors, it just takes a little thought. And realistically, a professional glazier too.

By law, door glazing has to be constructed from toughened glass for safety. Toughened glass means you can’t just take a glass cutter to your door and cut out a piece of glass ready for a cat flap to be installed.

Installing A Cat Flap into Glass That’s Toughened?

Toughened glass is cut first then toughened. Not the other way round. Cutting toughened glass is, well, tough to say the least. And the risk of it shattering if you try to cut or drill into it is very high.

Instead the best option if you want to fit a pet door into an existing pane of glass is to remove the pane altogether and have a new piece of glass cut, with the hole already in place.

Even if you do manage to fix a cat flap into any existing glass panels without them cracking, it’s a really challenging job and the finished product might keep you awake at night wondering if it will crack.

Plus the risk of damage to the door is higher and if it’s not sealed then cold air gets in (and of course hot air gets out).

A note on shape here too. A square cat flap fitting just won’t work well with glass doors or panes. For a cat flap fitting a glazier would need to cut a circle in the glass and insert a circular cat flap. Cutting a rectangle creates stress and the corners offer the opportunity for the glass to crack outwards. Many cat flap manufacturers will have the option for an adaptor to create a circular mount.

So make sure when you’re thinking about installing a cat flap in a single or double glazed unit, you take the shape into account.

Call An Expert

Removing the pane is also a better option if you are in a rental property. Explain to the glazier that you need the pane removed so it can be replaced later. When you come to move you can replace the original pane. It’s not necessarily the cheapest option for a rental property, but it’s an option.

But, in theory a cat flap installation can be fitted into most doors regardless of whether they are single glazing or double glazing glass panels.

Dog flaps can be a lot trickier than installing a cat flap into glass as they often require more space and most have square fittings, a shape that can’t be securely cut into glass. But again it’s not impossible. It all depends on the size and makeup of the door or area where you want to install it. There are solutions about if you need a dog flap installing.

There are even options for sliding patio doors or French doors when it comes to cat flaps. One company Pet-Tek offers a slimline solution that won’t stick out and block your doors from opening or closing.

Installing a Cat Flap in a UPVC Door Panel

Fitting a flap into a solid UPVC door panel is much easier, as long as you are  comfortable using tools (and of course, have the right ones).

Cat flaps come with a template for cutting, so you can get the hole the right size and then simply secure your cat flap into place. Even with a UPVC door, the best option is always to install from the start, rather than adding a flap to an existing door.

One of the most important things when installing a cat flap yourself is getting it at the right height. Don’t install it so high that your cat needs to take a running jump to get through it. If it’s too high, your cat probably won’t use it and you will have cut a hole in a perfectly good door for nothing.

Cat Flaps and Security

One of the most overlooked issues when it comes to a cat flap is security. A microchipped cat flap might stop other cats from coming into your house, but a cat flap does offer the perfect opportunity for people to reach in and hook keys that have been left with reach.

You will want to keep car or house keys out of sight and out of reach of your cat flap. And a little additional door security always comes in handy anyway.

Final Thoughts

Cat flaps get installed everywhere, these days, even in walls. So if you need a cat flap plan it out first. Think about the type of flap, the placement, the height from inside and outside. Think about the type of material your door is made from. It’s nearly always better to install it when the door is being built. But if this isn’t possible, then consider professional help.

There are many botched cat flaps out there. And your door or window could become seriously weakened if the job isn’t done well. If you want to install a cat flap into glass, you’ll need a glazier. It’ll be worth it in the long run.