Slate shingles are also called
slate tiles, the usual name outside the US. Slate roof shingles are relatively expensive to install but can last 80 to 400 years depending on the quality of the slate used, and how well they are maintained. The material itself deteriorates only slowly, and may be recycled from one building to another. The primary means of failure in a slate roof is when individual slates lose their peg attachment and begin to slide out of place. This can open up small gaps above each slate. A secondary mode of failure is when the slates themselves begin to break up. The lower parts of a slate may break loose, giving a gap below a slate. Commonly the small and stressed area above the nail hole may fail, allowing the slate to slip as before. In the worst cases, a slate may simply break in half and be lost altogether. A common repair to slate roofs is to apply '
torching', a mortar fillet underneath the slates, attaching them to the battens. This may apply as either a repair, to hold slipping slates, or pre-emptively on construction. Where slates are particularly heavy, the roof may begin to split apart along the roofline. This usually follows rot developing and weakening the internal timbers, often as a result of poor ventilation within the roof space. An important aspect to slate roofs is the use of a metal
flashing which will last as long as the slates. Slate shingles may be cut in a variety of decorative patterns and are available in several colors. Flagstone shingles are a traditional roofing material. Some stone shingles are fastened in place but some simply are held by gravity, so the roof pitch cannot be too steep or the stones will slide off the roof. Sandstone has also been used to make shingles.
Gallery of stone shingles File:Meerbusch - Lank - Hauptstr 19, Van-Haags-Hof - Detail Dach (3).jpg|Slate roofers guild emblem as an ornament made with slate roof shingles,
Meerbusch, Germany. Note the hip shingles act as a ridge cap. File:Kastanitsa roof.jpg|A typical flagstone roof in
Kastanitsa, Greece. File:DryStoneRoofConstruction.jpg|A dry laid stone roof in Switzerland ==Fibre cement shingles==