Midrexâs primary business is direct reduction ironmaking. We build DRI plants that work day in and day out, year after. year to provide value for our clients so that they can make. the most of their investment and maximize their profits for. years to come. The MIDREXÂ® Process 2. The MIDREXÂ® Process.
Quick Answer. The maximum interior height of an entry door threshold is 1/2 inch, and up to 3/4 inch on exterior siding doors where it is essential to keep water out, as stated by the United States Access Board. These height limits improve wheelchair access to buildings.
The standard width and height of a commercial door is three feet  wide and six feet, eight inches tall. Commercial doors are larger  than residential doors.  Actually m â¦ any commercial doors are 84 in height. Six feet eight is  normal for a residential door.2 people found this useful. The rough opening for the door and frame to fit into is 3 inches larger on the width and 1-1/2 inch o â¦ n the height which will allow for the door and jamb and also any necessary adjustment required to plumb and/or square the door unit.