They are sometimes made of clay, especially on hipped roofs, but on gabled roofs they are more frequently of squared or turned timber.
Weithiau maent wedi'u gwneud o glai, yn arbennig ar doeon slip, ond ar doeon talcennog yn amlach na pheidio maent wedi'u gwneud o bren wedi'i sgwario neu wedi'i droi.