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.
For a 6' 8 high door (80 inches) I like to frame my rough opening heighth at 82 3/4. This allows room for all the situations mentioned above. If your header material is a. double 2x12, holding it to the top plate will give you that heighth. Rough openings for door widths are pretty much standard. The rough opening width is 2 inches wider than the door itself. this allows room for the door jambs which are usually 3/4 thick. This gives you approximately 1/2 of play and shim room when installing a prehung door. For a 36 door (3' 0) the rough openig width would be 38.