sillcock

A sillcock, also called a hose bib, is an exterior water faucet connected to a building's potable water line. It provides a threaded outlet for attaching hoses and irrigation equipment and is typically mounted on an exterior wall near ground level. Sillcocks are common in residential, commercial, and industrial settings for outdoor tasks such as gardening, car washing, and landscape maintenance.

Most sillcocks are standard faucets with a valve stem operated by a handle on the exterior. A common variation is the frost-free or frost-proof sillcock, in which the valve seat is located inside the building and the stem extends through the wall to the outdoors. When the handle is turned, the valve inside opens, allowing water to flow while the interior valve remains away from the cold exterior.

Many codes require backflow prevention to protect potable water. Some sillcocks include built-in anti-siphon devices or must be installed with a separate vacuum breaker. Placement should consider exposure to freezing, sun, and physical damage, and frost-free models are preferred in climates with freezing temperatures. Accessibility for winterization and shutoff is also important.

Maintenance includes winterizing outdoor lines in cold climates, draining residual water, and inspecting for leaks around the packing nut or spout. Worn packings or washers can cause dripping; replacement may require turning off the main supply. If a sillcock is damaged or corroded, it should be replaced rather than repaired on site.

Common terms include hose bib, spigot, and faucet. The term sillcock emphasizes its mounting at the sill of a building or exterior wall.