https://menwiki.men/wiki/Fitti....ng_Cat_Flap_in_UPVC_
If you want to install a cat flap inside your home, it's recommended to work with an expert tradesperson. DIY projects often result in poorly fitted pet flaps that can allow in draughts or raise the cost of energy. SheffLOCK is able to put a cat flap on all types of doors, including wood, glass, uPVC composite and even exterior walls. It takes approximately two hours to put in the new cat flap. Pet flaps cost money A pet flap permits your cat to come and go whenever it wants. If the flap is not installed correctly, it could a