01
Build a useful sample brief
Ask a slater to provide the actual length, width, approximate thickness range, and photographs of the face and edge. Include the roof's location and any known installation or supplier records. Photograph representative pieces rather than only the most damaged one. Have any physical sample removed and handled by someone qualified to work on the roof.
02
Describe the purpose of the match
Explain whether the material is for scattered repairs, a visible extension, or replacement of an entire slope. These situations can call for different visual judgments. Ask the supplier what variation to expect across the proposed lot and whether the sample represents it. Keep the approved sample labeled with the source and date so later deliveries can be compared with the same reference.