For a replacement steel grating stair tread, record both the tread and the supporting stair interface. Copying only the outside rectangle can miss the hole pattern or leading-edge position that determines whether the replacement fits.
Use consistent measurement datums
Label the faces and points from which dimensions are measured. Record tread width and depth, end connection dimensions and hole locations. Distinguish hole centre dimensions from measurements to a plate edge and identify the front of the tread in every photograph.
Capture the surrounding arrangement
- Distance and geometry between supports.
- Existing fixing components and access to them.
- Leading-edge position and adjacent tread interfaces.
- Any obstruction affecting installation or removal.
- Differences between otherwise similar tread locations.
Record condition and uncertainty
Identify damage or corrosion that makes the old dimensions unreliable. If the stair has changed or the original specification is unavailable, ask for the required review before adopting the old tread as the production template.
Issue a marked replacement schedule
Give each distinct tread type a reference and quantity. Attach photographs and a dimensioned sketch, clearly marking unresolved measurements. Obtain agreement on the finished drawing before manufacture.
Use the tread drawing checklist for the specification and the quotation schedule to define supply scope.
