https://squareblogs.net/lightr....ocket14/adding-a-cat
https://sutherland-aycock-2.hu....bstack.net/cat-flaps
A popular choice for homeowners, a composite cat flap is an unsecure entry point for your pet. It also reduces the likelihood that unwanted animals will gain access to your home. However, adding a cat flap to your composite door requires knowledge and understanding of the door's construction. Any structural changes can weaken the integrity of the door, and also affect its thermal performance. The addition of a cat flap the com