|This article is about the current version of DF.|
Kilns are central to a surprisingly broad array of labors, the most obvious of which is the making of pottery and clay goods. All clay and porcelain items are produced at a kiln. This includes bricks, jugs, large pots, hives, statues, and general crafts, as well as instruments and instrument pieces if your particular world gen happens to generate them. You can enhance the value of these earthenware products by glazing them at a kiln, though this requires ash or cassiterite. Fresh clay can be acquired for use at a kiln with the "Collect Clay" order, assuming you have clay collection zones assigned.
Although kilns are not used in the production of glass itself, they are necessary for converting potash into pearlash, a necessary ingredient for making clear and crystal glass goods. Likewise, your hospital can benefit from a kiln's ability to turn gypsum, alabaster, selenite, or satinspar into plaster powder, though this also requires you possess an empty bag for each unit you wish to produce. If you want to make parchment for codex and scroll production, the calcium carbonate stones (calcite, chalk, limestone, and marble) may be processed into quicklime at a kiln, though this also requires spare bags.
Each action taken at a kiln consumes one unit of fuel. The specific skill used depends on the action taken. Creating earthenware items requires the potter skill. Glazing those items instead uses the glazer skill. Producing pearlash, plaster powder, and quicklime all use furnace operator. Collecting clay can be done by any dwarf with the item hauling labor active.
Kilns can be built from any fire-safe material. Once you designate a spot for your kiln to be built, a building designer will bring the material to the site and design the building before the actual mason (for stone and glass kilns) or metalworker (for metal kilns) comes along and builds it. Strangely enough, charcoal and coke are valid mason's materials for building a kiln, since their ignition point is above the cutoff for fire safety.
The overall value of the kiln building helps determine the strength of the good thought dwarves receive when admiring it. This value is determined by both the value of the material used in its construction, as well as the quality of both the architect's and builder's efforts.