https://telegra.ph/Fitting-a-C....at-Flap-in-a-UPVC-Do
https://www.openlearning.com/u..../lopezfalk-sm6ok3/bl
Adding a cat flap to your door is an important task to be handled by a professional. The doors are typically made from a thin, plastic exterior that is attached to an insulation-enhancing, soft polystyrene base. These materials are often difficult to cut. It is much simpler to put the cat flap inside an existing glass pane, or have the hole prepared in a new door. A glazier is capable of doing this for you. Easy to Fit If you have a cat