the off the shelf doors are actualy very good, we fitted one to a farm workshop it took a sustaned pikey attack till they gave up and went in through the roof,
£ and time wise youd be daft to try and make one, on a shipping container id make an angel frame out of heavy angel set it into the container then fit the provided door frame to that with bolts and silkaflex
£ and time wise youd be daft to try and make one, on a shipping container id make an angel frame out of heavy angel set it into the container then fit the provided door frame to that with bolts and silkaflex