S Definitions

Definition Categories

Saddle fitting

A saddle fitting is a connection between pipes where a new pipe is attached to an existing pipe by puncturing the existing pipe and clamping the new pipe to the existing pipe. Saddle fittings are sometimes used to tap existing water supply pipes for low volume applications such as refrigerator ice-makers and reverse osmosis water treatment systems. Saddle fittings are prohibited in drainage pipes, but are often found in low volume applications such as reverse osmosis water treatment system discharge tubing connection to trap arms.

Sanitary Tee

A sanitary tee is a tee fitting combined with a quarter bend fitting. A sanitary tee may have one or more side inlets


Service is a generic term describing conductors and equipment that deliver electricity to a building. Service drop and service lateral conductors and equipment (such as meters) are usually installed and maintained by the electric utility.

Service drop

The service drop describes overhead electrical wires beginning at the power pole and ending where the service drop wires connect to the service entrance wires. This is usually at the service point near the mast on the roof.

Service entrance wires

Service entrance wires run from the service point to the service equipment. In an overhead (service drop) system, the service entrance conductors are the conductors between the connection point at the utility’s overhead wires and the service equipment terminals. in an underground (service lateral) system, the service entrance conductors are the conductors between the service lateral and the service equipment terminals. If the utility’s meter and the service equipment are mounted in adjacent cabinets, then the service entrance conductors may be short wires or metal bars between the service equipment terminals and the utility’s meter.

Service equipment

The service equipment includes the circuit breakers, fuses, or switches that control and cut off power to the building’s entire electric system. Other terms for service equipmentinclude main service cut off and service disconnecting means. The service equipment may be located in the same cabinet as the main distribution panelboard or it may be located in a different cabinet.


Service lateral

The service lateral describes the utility’s underground electrical wires, often beginning at the utility’s transformer cabinet near the street and often ending at a meter cabinet.

Service point

The service point is where the utility’s service wires connect to the home’s service entrance wires. The service point in an overhead service drop is often where the utility’s wires connect to the service entrance wires near the mast on the roof. The service point in an underground service lateral is often at a meter cabinet. The service point is defined by the local electric utility and determines where the utility’s service and maintenance responsibilities end and where the homeowner’s service and maintenance responsibilities begin. The service point varies depending on the utility and on how electric service is supplied to the home.

Sill (sill plate)

A sill plate is a horizontal piece of wood that is supported directly on the foundation and is the bottom part of a wood-framed exterior wall. Sill plates are almost always made with treated lumber.


Sleepers are horizontal pieces of wood laid on concrete that provide a nailing surface for flooring. Sleepers are sometimes used to separate hardwood flooring from the moisture that can migrate through concrete.

Slip joint

A slip joint is a hand-tightened fitting at the inlet and outlet side of traps. Slip joints allow easy removal of the trap for cleaning. Slip joints must be accessible.

Smoke chamber

The smoke chamber is an area above the firebox between the throat and the chimney.

Smoke shelf

The smoke shelf is an optional dip at the bottom of the smoke chamber.


Soil is material in the plumbing drainage system that contains urine or fecal material.

Solar heat gain coefficient (SHGC)

SHGC is a measure of the amount of solar radiation that passes through a window. A lower SHGC means that less solar radiation passes through a window.


Solder (Soldering)

Soldering is a method of joining metal pipe (such as copper and brass) at temperatures that do not exceed 800° F. Soldering usually uses a tin alloy as the joining material. Soldered joints are weaker than brazed joints.

Sole plate

A sole plate is a horizontal piece of wood that is the bottom part of a wood-framed wall other than an exterior wall on the foundation.

Spa and hot tub

A spa or hot tub usually consists of a water-containing shell and a pump, heater, air blower, and other accessories. Spas and hot tubs may be located indoors or outdoors, but are not usually located in bathrooms. Spas and hot tubs are usually not drained after each use and are usually larger than whirlpool bath tubs.

Spa and hot tub (packaged or self-contained)

A packaged hot tub or spa includes factory fabricated water circulating, heating, and control equipment intended to operate a spa or hot tub.  A packaged spa or hot tub does not include the water-containing shell. A self-contained spa or hot tub is the same as a packaged system except that a self-contained system includes the water containing shell. The water-containing shell is usually fiberglass and is usually surrounded by a wood or fiberglass surround. These spas and hot tubs are usually located on the ground or raised on a deck or other suitable supporting structure. This contrasts with site-built spas and hot tubs which are usually in-ground concrete structures and are often built adjacent to a permanent swimming pool.


The span is the unsupported distance between framing members. Example: the span of a 120 inches long floor joist with 1 ½ inches bearing on each end support is 117 inches.  Example: the span of a sheet of sub floor between joists spaced 16 inches on center is 14 ½ inches. See also Roof span.

Spark Arrestor

A spark arrestor is a metal screen installed at the outside termination of a chimney. A spark arrestor is often installed with a rain cap. A spark arrestor helps prevent hot embers from escaping and starting a fire. A rain cap helps keep water from entering a chimney. Water can damage chimney materials. Spark arrestors and rain caps are recommended on all chimneys, but are not required by the IRC.


A stack is a vertical plumbing drain or waste pipe that extends one or more stories. A stack collects waste material from horizontal drainage pipes and conducts it to the building drain or other horizontal drain.

Stack vent

A stack vent is a dry vent that connects to a soil or waste stack above the highest horizontal drainage connection and may extend through the roof to the outdoors or may terminate with a stack-type air admittance valve.


A standpipe is a vertical pipe used as an indirect waste receptor. Standpipes are most often used as the receptor for a clothes washing machine.

Stop-and-Waste Valve

A stop-and-waste valve is a water supply valve with an opening that allows draining of the non-pressure side. These valves are most common in cold climates and are used to protect exterior water fixtures from freeze damage.

Street fitting

A street fitting has a female opening (hub) on one end and a male opening (spigot) on the other end. Most drainage fittings have female openings on both ends.

Stud , jack

A jack stud is a vertical support member in a wall that runs between the bottom of a header and the wall bottom plate and helps support the header.

Stud, king

A king stud is a vertical support member in a wall that runs beside a header between the wall top and bottom plates and helps support the header.


A surcharge on a retaining wall is a vertical load in addition to the retained earth. The load is usually additional earth above the top of the retaining wall, but the load could be imposed by a nearby structure such as a swimming pool or a building.


A swale is a ditch or depression intended to drain storm water runoff from a residential lot to the street or other storm water collection area.


A sweep is a drainage fitting used to make a 90° change in the direction of flow. A short sweep is the same as a quarter bend in plastic pipes. Short sweeps and quarter bends are different fittings in cast iron pipes. A quarter bend with a longer radius bend is sometimes called a long sweep or a long turn quarter bend.

Swimming pool (permanent)

A permanent swimming pool is any water-containing structure intended for recreational use that has a water depth greater than (>) 42 inches. All indoor swimming pools are defined as permanent swimming pools regardless of the water depth. Permanent swimming pools are usually fully or partially in-ground structures, but need not be so. This definition applies only to Chapter 42. See Appendix G for another definition of a swimming pool that applies to pool barriers.

Swimming pool (temporary)

A temporary or storable swimming pool is a water-containing structure intended for recreational use, constructed on or above ground, and has a water depth not more than (≤) 42 inches. This definition also includes water containing structures made using molded plastic or inflatable fabric walls.