How to Appraise Antique Slate Roofing Tiles

Determine which type of slate was used to make the antique roofing tiles. If you live on the East Coast, for instance, there is a good chance the slate comes from one of the states in your area. Examine the color of the slate, whether it contains any bands of other colors, and whether the slate feels extremely soft -- prone to flaws and breakdown -- or hard. Compare your slate color to reference images for better identification.

Consult local historical societies or online records for reference to antique slate roofs in your area, for instance, "Minneapolis 1920s slate roofing." Call local building supply salvage yards and ask if they carry your variety of roofing slate. Ask the price for both chipped and perfect pieces.

Call slate roof specialists in your area until you find one that repairs antique slate roofs with genuine antique replacement slate tiles rather than reproductions. Tell them whether your slate is still on a roof or if it is has been removed, as well as how it is stored and how much you have on hand. Send them photos of your slates. Ask them the price they'll pay you for slates based on your slate information (wholesale price), and how much they charge for similar replacement slates (retail price). Contact another slate roofing specialist in your area, if there are more, and ask the same questions. Your tile appraisal value is the range between the average wholesale and retail slate price.