The file must clearly call out the overall width, height, and length of the staircase. It should also specify the thickness of the treads, risers, and stringers, along with the size and location of any landings or platforms.
Use these standard layers for a professional CAD file: double stringer staircase detail dwg
These can be made from steel (using C-channels, UPN profiles, or rectangular tubes) or wood (typically 2x12 lumber). The file must clearly call out the overall
Keep stringers, treads, and dimensions on separate layers. double stringer staircase detail dwg
For open-riser configurations, the space between the treads must not allow a 4-inch (102 mm) diameter sphere to pass through. This requires adding a small vertical steel kick plate or a thick tread block to close the gap legally.