Jefnik Windows and Doors is your source for new doors and replacement doors. We provide sales and installation of steel doors, fiberglass doors and patio doors in standard and custom shapes and sizes and in a variety of colours and finishes. Jefnik Windows and Doors is based in Mississauga Ontario and proudly serves Mississauga, Oakville, Milton, Brampton, Etobicoke, Toronto and the surrounding GTA.