Glossary
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ABS Plastic
Black plastic pipe and fittings. Usually used in waste water and drainage systems. Introduced in the 1960's; popular for new residential construction and remodeling.
Air Conditioning
The process of treating air to control simultaneously its temperature, humidity, cleanliness and distribution.
Air Filter
A furnace filter installed in line with the cold air return which filters out dust and debris and prevents its re-entry into the occupied interior.
Air Gap Vent
The fitting for an air gap vent for the dishwasher drain separation is located above the kitchen sink. This air gap assures separation of the supply water from the waste water.
Air Return
A furnace duct through which interior cool air returns to the furnace. This cool air is then circulated past the heat exchanger, warmed, and distributed through the ducts.
AMP
The rate of flow of electricity through wire. It is measured in terms of amperes.
Anchor Bolt
A bolt used to secure a wooden sill plate to a concrete or masonry floor or wall. The purpose of the bolt is to limit the ability of the framing to move independently of the foundation in the event of seismic activity.
Angle Stop
A shut-off valve arranged in 90-degree configuration. It is used to shut off the flow of water to a fixture.
Asbestos
A naturally occurring mineral fiber extensively used in construction. Nearly every building contains asbestos in some form. It may be found in vinyl flooring, patching compounds and textured paints, sprayed acoustic ceilings, acoustic ceiling tiles, stove insulation, furnace insulation, pipe insulation, wall and ceiling insulation, roofing shingles and siding as well as appliances.
Ceiling Joists
Ceiling joists are structural members which support the finished ceiling and often serve as important components of the roof structure.
Combustion Air Supply
Combustion air provides the oxygen for fuel burning appliances. Adequate ventilation around all fuel burning appliances is vital for their safe operation. The air can come from inside or outside, provided that industry standards are met.
Condensation
Beads or drops of water that accumulate on the inside of the exterior covering of a building when warm, moisture-laden air from the interior reaches a point where the temperature no longer permits the air to sustain the moisture it holds.
Conductor
An electrical wire capable of carrying current.
Conduit
A hollow pipe (metal or plastic) casing through which electric wires run
Cracked Mastic
Cracks in the roof cement coating used to seal the roof connections and penetrations. This creates a condition conducive to moisture penetration and subsequent leakage.
Creosote
One of the by-products given off when burning wood. Creosote condenses inside the fireplace chimney walls. It is highly combustible and, if sufficiently heated, can ignite and start a flue fire.
Doubled-Up Branch Circuit
Two circuits controlled by one overcurrent protection devise This wiring method increases the possibility of tripping the overcurrent protection device. Each circuit should be separately fused with an overcurrent protection device of appropriate amperage.
Ducts
Metal piping used for distributing warm or cool air.
Eaves
The edges of the roof that extend beyond the external walls, creating a shaded, exposed underside. The eaves typically have a horizontal underside called a soffit, which may be vented to allow air to circulate through the attic or roof space.
Evaporation Coils
The part of the air conditioning system where the refrigerant returns to gaseous form. Frequently located in the furnace plenum.
Fascia
The long, straight board that runs along the lower edge of the roof. The fascia is fixed directly to the lower ends of the roof trusses and usually carries all the guttering.
Fire-Restrictive Barrier
A fire-resistive separation/barrier whose purpose is to prevent the spread of fire from the garage (or furnace/water heater location) into the living areas. Present building code requires a one-hour fire-resistive barrier between the garage and the occupied interior. The risk of a fire starting in the garage is significant enough to warrant recommending that a one-hour fire-resistive barrier be installed.
Flashing
Material used at connections and penetrations in a roof or wall to prevent leakage.
Flexible Gas Connector
Older installations of gas-fired appliances often use rigid gas piping. This piping is subject to damage in the event of seismic activity. We recommend that all gas-fired appliances be equipped with flexible gas connectors. This should help reduce damage in the event of an earthquake.
Form Wood
Wood used in the forming of a concrete foundation or retaining wall, typically removed after the concrete has set. If it is left in place, it can lead to the infestation of wood-destroying pests. We recommend that all form wood be removed from the crawl space and foundation areas.
Forced Air Furnace
Forced air furnaces operate by heating a stream of air moved by a blower through a system of ducts. Important elements of the system include the heat exchanger, exhaust venting, blower, controls, filters and ducting.
Foundation
Construction below or partly below grade, which provides support for exterior walls or other structural parts of the building.
Fuse
An overcurrent protection device with a circuit opening fusible member directly heated and destroyed by the passage of too much current through it.
Galvanized Pipe
Steel pipe with a protective zinc coating. Used for supply of domestic water and waste and vent piping.
Grade
The ground level around a structure. When the ground is less than six inches below the top of the foundation it is considered a faulty or marginal grade. A faulty or marginal grade can lead to moisture damage and/or pest control problems.
Grounded
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in the place of the earth.
Gusset
A strap made of metal or wood attached at the connection of foundation area beams and posts. Gussets will help limit the framing's ability to laterally rack in the event of seismic activity.
GFCI
A safety device which monitors the difference between current flowing throughout the hot and neutral wires of a receptacle. If there is an imbalance of current greater than five milliamps, the current will be cut off in 1/40 of a second. GFCI protection is recommended in the garage, outdoor and bathroom receptacles. We also recommend that all pool and spa equipment have GFCI protection. We further recommend that all kitchen receptacles within six feet of a sink above a countertop be equipped with GFCI devices. This will reduce shock and short hazards.
Heat Exchanger
A device by which heat is exchanged from one heat-carrying medium to another without contact between the two media.
High Loop
A high loop is a method of backflow prevention where the drain line runs from the dishwasher to the highest point beneath the sink.
Hold Downs
The steel device or hardware that is installed at the end of a plywood shear wall. Earthquakes tend to affect a structure in two ways. They shake a building which can weaken the structure's frame. They also heave the ground up suddenly and generate forces that can lift an entire building off its foundation. Hold downs help resist both types of movement.
Joists
Parallel, horizontal boards laid edgewise from wall to wall to support the boards of a floor or ceiling.
Main Disconnect
A device by which the electrical system can be disconnected from its source of supply. Six or more branch circuits require a main disconnect device.
Mastic
Asphalt material used to seal around roof connections and penetrations.
Outlet (Electrical)
A switch, light or receptacle.
Overfused
A fuse or breaker too large for the rated capacity of the circuit. This allows too much current (heat) to flow throughout the conductor (wire) before the overcurrent protection device blows or trips. This is hazardous. The rated capacity of the circuit may not have been exceeded, however, increased demand on the circuit may result in the conductor overheating, which can cause a fire.
Penetrations
Any projections through a surface necessitating flashing or caulking such as plumbing vents and skylights.
Plenum
A large duct or air chamber in which the hot air from the furnace is distributed to the ducting and through the ducts to the registers.
Receptacle
An electrical device to receive the prongs of a plug and which is connected to an electric circuit.
Register
A fixture installed at the end of a duct which controls and directs the flow of air into a room.
Roof Drain
A typical roof water drainage system consists of a 4" diameter solid (non-perforated) pipe installed underground and directed continuously downhill to a point of discharge. The purpose of the drain system is to divert water from the roof away from the foundation, thus helping to prevent water infiltration into the Crawl Space or Interior living spaces located below grade.
Roof Pitch
The degree of slope of a roof.
Running Splice
An electrical connection made without proper protection.
Settlement
Settlement is that instance in which some portion of the foundation drops below the original "as built" grade. This occurs as a result of a loss of bearing - compaction of fill, erosion or supporting soil, and/or dehydration (shrinkage or supporting soil).
Soffits
The material beneath the eave that connects the far edge of the roof to the exterior wall of the house. They are often vented to allow air to circulate through the attic or roof space. Besides being underneath the eaves, soffits can also be on the underside of a porch roof.
Spalling
Flaking off of the surface of brick or concrete, having cracked and delaminated from the substrate. There are a number of reasons why spalling occurs including freeze thaw cycling or exposure to fire.
Stud
A vertical, framing member in a wall or partition, usually spaced from twelve to sixteen inches apart.
Surface Drain
Designed to collect and divert roof runoff and other surface water away from a building. It is typically installed in a solid pipe and normally flows continuously downhill to a point of discharge.
Temperature/Pressure Relief Valve
A safety valve designed to open under excessive pressure or temperature. Commonly used in water heaters and boilers.
Thermostat
An automatic heating/cooling control device, often controlled by clocks or computers to set back the temperature during certain time periods as a fuel-saving measure.
Trap
A fitting to provide a liquid seal that prevents the back passage of gases, without materially affecting the flow of sewage or water through it.
Trip Hazard
An irregularity in a walking surface exceeding one inch (1") in height. All walking surfaces should be maintained, free of a vertical surface change of 3/4" or more, in the interest of public and personal safety.
Underlayment
1) Building material, generally paper or felt, used as a protection against the passage of air and moisture, typically used under roofing and siding materials. 2) Smooth surface plywood or particle board used under flooring materials.
Valley
A depressed angle formed where the bottom of the roof planes meet.
Vapor Barrier
A material or paint applied to a wall, floor or ceiling to prevent the passage of moisture. Plastic vapor barriers are sometimes applied over the subarea soil. This helps create a dry air space between damp soil and wood framing and limits the amount of moisture able to rise into the framing, thereby reducing moisture damage. A plastic vapor barrier also provides a reasonable surface upon which to crawl in the event of needed access to a moist subarea. Finally a plastic vapor barrier tends to keep moist soil from drying out completely and reduces the subsequent shrinkage and cracking that often occurs. This reduces the settlement often associated with expansive soil subject to fluctuating moisture content.
Vegetation Encroachment
Vines and/or shrubbery that cover the exterior finished siding, foundation vents, decks, stairways and electrical equipment. This vegetation can cause damage. We recommend that all shrubbery against sidewalls and foundation vents be cut back. Tree limbs and branches that have overgrown or surround the electrical service entrance conductor wires should be removed.
Vent (Plumbing)
A pipe installed to provide a low of air to or from a drainage system and to minimize possibilities of trap siphonage and back pressure.
Voltage
Electric power. The greater the speed at which electrons travel, the more power present (240 volts is more powerful than 120 volts.)
Wall Cracks
Hairline cracking in the interior walls and ceiling, as well as minor sloping and sagging of floors and door casings, should be expected as a result of ordinary settlement and expansion of the foundation system, structural framing, and soil.
Watt
The amount of electricity flowing through a line, measured in terms of watts. Volts multiplied by amps equals watts.
Whole House Fan
An in-ceiling ventilation fan that exhausts the interior rooms of stale air and allows proper ventilation of the home. The fan should be equipped with a timer, set to operate twice per day (ex. morning and night) for approximately one hour at a time.