Fitting a Cat Flap

Fitting a cat flap may seem like a daunting task, particularly if you are a DIY novice. But it’s really only a case of cutting an accurate hole, the actual fitting is very easy.

Pick Your Spot

First choose the door or window where you are going to put the cat flap. All cat flaps come with instructions that will cover the size of the hole. Many will have a paper or cardboard template to make it easier.

Get an idea of the distance between your cat’s stomach and the ground, and make sure you don’t have the lower edge of the cat flap too much higher than this. At the same time, be aware that the cat flap itself will be significantly larger than the hole, so make sure you have clearance from any mouldings or sills on the lower edges of the door. Make sure you check for clearance on both sides of the door!

Cutting the Hole

Once the hole is marked you need to cut it out and how you do this depends on the tools available to you. Wear eye protection and any other safety gear appropriate to the job and the material you are cutting.

If you have a jigsaw and you have used it a number of times you may be confident enough to go for the straight cut. Select the slimmest blade you have and start the motor with the blade at an angle to the panel.

Press the blade against the panel and it should start the cut, allowing you to slowly move the blade through the panel and into the correct cutting position. Then go around the hole in the normal way.

What if You Don’t Have a Jigsaw?

Without a jigsaw you need to drill a starting hole somewhere inside where the hole will be, then get a keyhole saw (like a hacksaw but with just a handle at one end, no frame) to cut around the template outline. Make sure you drill the pilot hole on the inside of the circle, on the waste side. You can also drill a number of pilot holes around the edge and then join them up with the saw, that might be faster.

Or if you have a drill that makes large circles, or a hole saw attachment, you can drill big holes that almost join up, all around the inside of the template line. The waste should then push out with a little encouragement.

Finishing Off and Fitting

If you’ve used either of those two last methods you will have quite a bit of filing to do to remove the waste. But there is usually quite a bit of leeway in the hole dimensions, as the front and back of the cat flap will overlap the hole. Just keep offering up the cat flap to try it so that you only remove as much as you need to.

Once the hole is cut it’s simply a case of mounting the pieces of the cat flap according to the instructions. They usually clip or screw together.

Double-Glazing Hassles

The downside of cat flap fitting these days is that many doors are uPVC double-glazed and it’s not really possible to do a DIY job on these. If you are looking at a back door with a glazed panel above and a solid panel below, it can be done, although it’s easier if the panel is solid.

If that lower panel is double-skinned, like a glazed unit but with plastic sheet instead of glass, it can still be done. But you will lose the vacuum in the gap between the panels and therefore the heat insulation properties of the door will be lowered. You might consider that not much of a loss if you are putting a cat flap in anyway.

Get the Professionals In

But if the section where you want to put the flap is a uPVC double-glazed unit, it really will be much better to get a professional in to do the job. They will come and measure up the cat flap and the door (or window) then go away and manufacture a replacement unit, coming back to fit it within a week or so.

So that’s the story, tackle it yourself if you feel confident enough, but definitely call in the experts if it’s a double-glazed back door. But one way or the other your pussies will then be able to come ad go as they please.