Aluminum Roof Hatch Designed to Provide Convenient, Economical Access to the Roof of a Building. Each unit comes with an insulated, self-flashing, 12″High curb and a staple for a padlock on the inside and outside. Each unit is supplied with lift assisting mechanisms and an automatic hold open arm. 1 Latch. Mill Finish. 56″W x 56″H Outside Flange Dimensions. 48″W x 12″D x 48″H Return Flange Dimensions.