A Cat Door Fitted Into Glass for a New Belmont Cat Enclosure

A customer in Belmont had just had a brand new enclosure built for her cat. Frame up, mesh over the top, a safe run outside where the cat could sit in the sun without getting near a road.

The only thing missing was a way for the cat to actually get into it. That is where we came in, and the way in was going to be through the glass.

Working inside a finished enclosure

The enclosure was already built and netted by the time we got there. That is the normal order of events. People build the run first, enjoy it for a week, and then realise the cat still has to be carried out through the back door every time.

It does change how the job is set up. The window is now sitting inside a mesh cage, so there is no working in the open and no swinging a sheet of glass around from outside. Glass, tools and the old frame all have to come in and out through the enclosure opening, and the new pane has to be walked in and lifted into place in a space you cannot step back from.

None of that is a problem when you know about it beforehand. It is only a problem when a glazier turns up expecting a clear run at the window and finds a cage in front of it. The photos we ask for up front are how we avoid that.

A pet door in glass means a new pane, not a hole in the old one

This is the part that surprises most people, so it is worth explaining properly.

You cannot cut a hole in a pane of glass that is already installed. And if the glass is toughened, you cannot cut it at all once it has been through the furnace. Toughening is the very last step in making it. The size, the edges and any cutouts all have to be done beforehand, because putting a cutter or a drill anywhere near it afterwards will shatter the whole panel into thousands of pieces in about a second.

So a pet door in glass works the other way around to what people picture. We measure the opening, the new pane is made to size with the pet door cutout already in it, and then the old glass and frame come out and the new pane goes in with the door fitted through it. That is exactly what Josh is doing in the photo above, taking the old glass and frame apart to clear the opening.

It also means the glass type gets decided at that point rather than assumed. Glass down near floor level often has to be safety glass under AS1288, and a pet door is by definition at floor level, so it is worth getting right rather than matching whatever happened to be in there from decades ago.

Why we used a Transcat

We fitted a Transcat cat door on this one. It is one of the most trusted and popular pet doors going, and the important part is that it was designed for glass from the start rather than being a timber door product that someone has adapted to fit.

The round shape is a big part of why. A circular cutout has no corners, and corners are where stress gathers in a sheet of glass. A round hole spreads that load evenly all the way around its edge, which is what you want in a panel that is going to be sitting in a frame through hot days, cold nights and a cat throwing itself through the middle of it several times a day for the next fifteen years.

It also has a closing panel, so the door can be shut when the cat needs to stay in or the weather is coming in sideways.

Five business days from approval

From the customer approving the quote to the cat door being in and working was five business days.

Almost all of that is the glass being made. Once the new pane with the cutout arrives, the install itself is a morning. That is the honest timeline for a pet door in glass and it is worth knowing when you are planning around it, because it is not the same as an emergency job where we can be there the same day. There is nothing to rush when the panel does not exist yet.

Five days is quick for made to order glass with a cutout in it. It is not quick if you assumed it was a same day job and the enclosure has been finished and unusable for a fortnight already.

If you are building a cat enclosure

A few things worth knowing before the enclosure goes up rather than after.

Work out where the cat door is going early. It is much easier when you can still choose which window or door panel it goes through, instead of being stuck with whichever one ended up inside the enclosure. Ground floor windows, laundry doors and sliding door panels are all fair game.

Check what the glass is. If it is an old timber window there is a good chance it is plain float glass, and the replacement will need to be safety glass at that height regardless of what came out.

Think about the cat rather than the doorway. Flap height off the floor matters more than most people expect, particularly for older cats and for kittens who will grow into it.

And get the door sorted before the mesh goes on if you can. It is not that we cannot work inside a finished enclosure, this job was done inside one, it just gives everyone more room.

Getting one quoted

Send us a photo of the window or door you are thinking about, stand back far enough to get the whole frame in, and tell us your suburb. From that we can usually tell you the glass type, whether the panel suits a pet door, and what it will cost supplied and installed without needing to come out first.

We did a similar one on the other side of the bay for a greyhound, which you can read about in our Drysdale pet door install, and there is more on sizes, brands and the sorts of panels we fit them into on our pet door installations page.

Belmont is five minutes from us, so if you are local have a look at our Belmont pet doors page. We cover Belmont, Highton, Grovedale, Newtown and the rest of Geelong as part of the normal run.