Glossary, 121 terms
Home inspection terms: T
Each definition is the Key Term from the lesson named under it. Where two lessons define a term for different uses, both are here.
- T1-11
- A name often used for plywood panel siding, from 1 inch indentations and 11 inch raised sections; it does not describe the material accurately.
Lesson 4B, Fiber Cement, Hardboard, Insulbrick, Stucco, EIFS, Vinyl, Wood and Wood Structural Panel Siding - Tab
- A removable piece in the dead front cover that closes an unused breaker space.
Lesson 24C, Panelboard Defects, Subpanels and Problem Panels - Tabs (twistouts)
- Metal pieces in the dead front cover, removed to install a circuit breaker.
Lesson 23A, Electrical Terms and Basic Electricity - Tack strip
- A wood strip with small spikes, nailed to the floor, that holds carpet at the perimeter of a room.
Lesson 17B, Interior Doors and Floor Coverings - Tail joists
- The shortened joists, interrupted by a floor opening, that a header carries.
Lesson 12A, Floor Framing, Spans, Bearing, Notching and Boring - Tail piece (tailpiece)
- The vertical pipe from a sink outlet to a trap or to a fitting leading to one.
Lesson 34A, Plumbing Scope and Plumbing Terms - Tailpiece
- The pipe below a sink outlet, into which the lever of a pop-up stopper is inserted.
Lesson 35C, Sinks - Tankless coil
- 1. A type of domestic hot water equipment, distinct from a demand water heater and a storage tank.
Lesson 19D, System Descriptions and Inspection Methods - 2. A finned copper coil mounted inside the boiler that heats domestic hot water, essentially another heat exchanger.
Lesson 33B, Hot Water Heating Systems - 3. A finned copper coil mounted inside the boiler that heats domestic water; in effect another heat exchanger.
Lesson 33C, Steam Heating Systems and Distribution Piping - Taping and bedding
- The first drywall finishing stage: tape and joint compound on seams and inside corners, compound alone on fastener indentations.
Lesson 17A, Interior Walls, Ceilings, Drywall, Plaster and Trim - Tar and gravel
- A name often used for a built-up roof membrane.
Lesson 9A, Low Slope Roofing: Built-Up Membranes and Roll Roofing - Target market
- The people a marketing message is aimed at.
Lesson 22, Ethics, Starting a Business and Marketing - Task
- An action the home inspector takes, listed under a domain with its own weight.
Lesson 1, Course Introduction and NHIE Overview - Tee fitting
- The fitting at a septic tank outlet through which effluent leaves.
Lesson 38D, Septic Systems - Tee-wye
- A fitting like a wye, with its inlets at 90 degrees to the pipe.
Lesson 37B, DWV Fittings, Cleanouts and Defects - Telescoping column
- A column with one section fitting into another, usually considered a temporary support.
Lesson 11B, Forces and Soils, Footings, Piers and Columns - Temperature drop
- The fall in air temperature across the evaporator coil; it reflects the sensible load only.
Lesson 28B, Cooling Systems: Inspecting Equipment and Typical Defects - Temperature limitation system
- The solar water heating component that limits fluid to 180 degrees F or less where it enters, or exchanges heat with, a pressurized vessel in the building.
Lesson 27B, Alternative Energy Systems: Solar PV, Wind and Solar Water Heating - Temperature limiting device
- A device that limits water temperature; on a bidet the limit should be 110 degrees F.
Lesson 35D, Toilets and Bidets - Temperature relief valve
- The relief valve required on a swimming pool heater.
Lesson 36C, Demand, Oil and Heat Pump Water Heaters, Relief Valves and Drain Pans - Temperature/pressure relief (TPR) valve
- The relief valve required on every storage tank water heater, that opens at 150 psi or 210 degrees F; also called a T&P valve.
Lesson 36C, Demand, Oil and Heat Pump Water Heaters, Relief Valves and Drain Pans - Temperature/pressure relief valve
- A relief valve that may be used on a steam boiler, usually rated 15 psi/250 degrees F.
Lesson 33E, Steam Boiler Components, Solid Fuel and Related Components - Temperature/pressure relief valve (TPR)
- The relief valve required on a storage tank water heater.
Lesson 36A, Domestic Hot Water, Storage Tank Basics and Components - Tenon
- A projection on a framing member designed to fit a mortise.
Lesson 12E, CMU, Brick, ICF, SIPs and Uncommon Wall Materials - Tension force (load)
- A pulling or stretching force on a member.
Lesson 11A, Structural Scope and Terms - Terminal bars
- Metal bars where neutral conductors and EGCs are mounted.
Lesson 23A, Electrical Terms and Basic Electricity - Test administrator
- The company that administers the NHIE under contract with a state or with EBPHI.
Lesson 43, Scheduling, Taking and Passing the NHIE - Test center manager
- The person a candidate reports to on arrival and tells about a problem during the examination.
Lesson 43, Scheduling, Taking and Passing the NHIE - Textured finish
- A machine-sprayed drywall finish with a rough appearance.
Lesson 17A, Interior Walls, Ceilings, Drywall, Plaster and Trim - Thermal barrier
- A covering over foam plastic insulation that protects more against ignition and burning than an ignition barrier.
Lesson 12C, Wall Systems, Fireblocking and Fire Separation - Thermal break
- A feature of a metal window or door frame that reduces heat conducted through the metal.
Lesson 15A, Insulation Defects, Water-Resistive Barriers, Radiant Barriers and Fenestration - Thermal bridging
- 1. Heat conduction through framing components; more pronounced in steel than in wood.
Lesson 12E, CMU, Brick, ICF, SIPs and Uncommon Wall Materials - 2. The effect of wood framing, with its relatively poor R-value, in an insulated wall, floor, or ceiling assembly.
Lesson 14A, Insulation Scope and Terms, R-Value and How Insulation Works - Thermal bypass valve
- A valve at a fixture, joined to both supply pipes, that opens below a set temperature so water can circulate.
Lesson 35F, Water Treatment Devices and Hot Water Circulation - Thermal cutoff switch
- A device in a recessed light that shuts off the light when it overheats.
Lesson 26B, Switches, Lights and Ceiling Fans - Thermal cutout switch
- The switch in a distributed electric heater that, when defective, is a possible cause of excessive heat.
Lesson 33A, Electric Heating Systems - Thermal expansion
- 1. The increase in water volume as water is heated.
Lesson 34A, Plumbing Scope and Plumbing Terms - 2. The increase in the volume of water as it is heated.
Lesson 36D, Water Heater Installation, Seismic Bracing, Thermal Expansion and Defects - Thermal expansion device
- A tank or valve that lets heated water expand in a closed system without damage to the water distribution system.
Lesson 36D, Water Heater Installation, Seismic Bracing, Thermal Expansion and Defects - Thermal expansion tank
- 1. An air-filled closed vessel that absorbs the expansion of heated water.
Lesson 34A, Plumbing Scope and Plumbing Terms - 2. A tank, usually about 2 gallons in a house, in which a bladder keeps pressurized air apart from the water.
Lesson 36D, Water Heater Installation, Seismic Bracing, Thermal Expansion and Defects - Thermal expansion valve
- A valve that opens at a set pressure to let water drain, built into a cold water shutoff or a toilet fill valve.
Lesson 36D, Water Heater Installation, Seismic Bracing, Thermal Expansion and Defects - Thermal mass
- The heat-slowing bulk of a thick wall.
Lesson 14A, Insulation Scope and Terms, R-Value and How Insulation Works - Thermal-magnetic-trip circuit breaker
- A breaker that uses both magnetic-trip and thermal-trip technology; the modern house breaker.
Lesson 24B, Overcurrent Protection, GFCI and AFCI - Thermal-trip circuit breaker
- A breaker that detects an overcurrent by the heat it produces.
Lesson 24B, Overcurrent Protection, GFCI and AFCI - Thermistor
- The electronic sensor a digital thermostat uses to sense air temperature.
Lesson 28C, Cooling Systems: Condensate, Line Sets and Thermostats - Thermocouple
- A pilot flame sensor that bends when heated, completing a millivolt circuit so the gas valve can open.
Lesson 36B, Electric and Gas Storage Tank Water Heaters - Thermoplastic
- The class of material that CPVC and PEX belong to.
Lesson 34B, Pipe Supports, Copper, CPVC, Galvanized Steel and PEX - Thermoplastic membrane
- A single ply membrane, including those made from thermoplastic olefins (TPO) and polyvinyl chloride (PVC); uncommon in residential construction.
Lesson 9B, Low Slope Roofing: Modified Bitumen, Foam and EPDM - Thermoset membrane
- A rubberlike single ply membrane that returns to its original shape after stretching, such as EPDM.
Lesson 9B, Low Slope Roofing: Modified Bitumen, Foam and EPDM - Thermostat
- 1. A switch that turns the HVAC system on and off in response to air temperature at the thermostat.
Lesson 28C, Cooling Systems: Condensate, Line Sets and Thermostats - 2. A separate, replaceable device that controls a heating element; on a gas water heater, the thermostat sensor controls tank water temperature.
Lesson 36B, Electric and Gas Storage Tank Water Heaters - Thermostatic expansion valve (TXV or TEV)
- The metering device in most modern standard efficiency systems, controlled by an equalizer.
Lesson 28A, Cooling Systems: Understanding the System - Thermostatic trap
- A trap on every distribution device of a two pipe system that lets air and cool water out as the device warms.
Lesson 33D, Steam Distribution Components, Vents and Traps - Thimble
- Flashing for an appliance vent at a wall or roof.
Lesson 4C, Exterior Trim, Flashing and Sealants, Eaves and Cornice - Thimble (roof jack)
- Part of the flashing for a flue that passes straight through the roof.
Lesson 40A, Factory-Built Fireplaces and Chimneys - Thin film
- Newer PV technology that builds solar cells into roof coverings and other building materials.
Lesson 27B, Alternative Energy Systems: Solar PV, Wind and Solar Water Heating - Threaded adapter fitting
- 1. A threaded fitting that joins one pipe material to another, such as CPVC to galvanized steel.
Lesson 34B, Pipe Supports, Copper, CPVC, Galvanized Steel and PEX - 2. A fitting that may connect cast iron to galvanized steel.
Lesson 37A, DWV Rules and Pipe Materials - Three phase electrical service
- Service with one grounded conductor and three energized conductors, used mostly in commercial and industrial buildings.
Lesson 23A, Electrical Terms and Basic Electricity - Three-coat cement stucco (hard coat, exterior plaster)
- Stucco applied as scratch, brown, and finish layers on wire lath, approximately 7/8 inch thick in all.
Lesson 4B, Fiber Cement, Hardboard, Insulbrick, Stucco, EIFS, Vinyl, Wood and Wood Structural Panel Siding - Three-light receptacle tester
- A tester meant to show whether the wiring of a receptacle is correct; some models have an added button that tests GFCI receptacles and GFCI circuit breakers.
Lesson 20, Inspection Tools and the Inspection Process - Three-tab strip shingle
- The least expensive asphalt shingle style, with a flat profile and usually a 20 year warranty.
Lesson 8A, Steep Slope Roofing: Asphalt Shingles and Tile - Threshold
- 1. The piece installed on top of a door sill.
Lesson 5A, Exterior Doors and Safety Glazing at Doors - 2. The piece across the bottom of a door opening, below the bottom rail of the door.
Lesson 17B, Interior Doors and Floor Coverings - Throat
- The opening from the firebox into the smoke chamber.
Lesson 39A, Fireplace Types and Terms, Firebox, Hearth and Clearances - Through-wall unit
- 1. A permanently installed room cooling unit set in a wall opening, and in scope.
Lesson 28A, Cooling Systems: Understanding the System - 2. A unit that cools, and sometimes heats, one room or area; permanently installed, so in scope.
Lesson 28B, Cooling Systems: Inspecting Equipment and Typical Defects - Tieback
- The buried member that connects a retaining wall to its deadman and resists lateral force on the wall.
Lesson 2A, Site Scope, Terms and Retaining Walls - Tieback anchors
- A wall repair of rods or cables through the wall to a helical anchor in the yard.
Lesson 11D, Foundation Repairs, Crawl Spaces and Slabs - Ties
- Metal bars that hold concrete forms together.
Lesson 2A, Site Scope, Terms and Retaining Walls - Tile
- A generic term for many products with different properties.
Lesson 17B, Interior Doors and Floor Coverings - Timber framing
- 1. A framing system of large wood beams and posts connected with mortise-and-tenon joints.
Lesson 12C, Wall Systems, Fireblocking and Fire Separation - 2. A framing system of large beams and posts joined with pegged mortise-and-tenon joints.
Lesson 12E, CMU, Brick, ICF, SIPs and Uncommon Wall Materials - Tin-coated copper
- Copper wire with a tin coating that resembles solid-conductor aluminum; peak use in the 1940s and 1950s.
Lesson 25B, Older Wiring: Knob and Tube, Cloth NM and Aluminum - Toe kick (toe strip)
- The recessed strip along the foot of a base cabinet.
Lesson 18B, Cabinets, Countertops and Smart Home Scope - Toilet (commode, water closet, WC)
- The fixture that takes in human excrement and sends it to the drain pipes; commode is a regional word in the Southeast and South.
Lesson 34A, Plumbing Scope and Plumbing Terms - Ton (of refrigeration)
- 12,000 Btu per hour of capacity.
Lesson 28A, Cooling Systems: Understanding the System - Tongue and groove
- A panel edge style that supports sheathing edges between floor joists.
Lesson 12A, Floor Framing, Spans, Bearing, Notching and Boring - Top chord bearing
- 1. A floor truss support in which a vertical member fastened to the top chord, or a top chord extended past the truss end, rests on the support.
Lesson 12B, I-Joists, SCL, Glulam and Floor Trusses - 2. A roof truss arrangement in which the truss bears at its top chord; used for some roof trusses.
Lesson 13B, Roof Framing Defects, Trusses and Attic Access - Top plate
- The horizontal framing at the top of a wall, usually doubled.
Lesson 12D, Wood Wall Framing, Bracing and Wall Defects - Top rail
- 1. The horizontal sash member at the head jamb.
Lesson 5B, Windows, Window Flashing, Glazing, Window Wells, Escape Openings and Fall Protection - 2. The top component of a guard, formed by the handrail.
Lesson 18A, Stairs, Ramps, Handrails and Guards - Torsion spring
- The more common garage door spring type, a single spring over the door near its center.
Lesson 7, Garage Vehicle Doors and Operators - Torsion tube
- A tube that runs through a torsion spring and connects the roller drums.
Lesson 7, Garage Vehicle Doors and Operators - Tower style flush valve
- A flush valve with a cup that covers the opening.
Lesson 35D, Toilets and Bidets - Townhouse
- A single family attached dwelling; a building type, not a form of ownership.
Lesson 11A, Structural Scope and Terms - TPR extension pipe
- The pipe extending from the TPR.
Lesson 36A, Domestic Hot Water, Storage Tank Basics and Components - TPR valve
- The relief valve on a water heater.
Lesson 36D, Water Heater Installation, Seismic Bracing, Thermal Expansion and Defects - Track light
- A light mounted on a metal strip, usually on the ceiling.
Lesson 26B, Switches, Lights and Ceiling Fans - Transfer (jumper)
- A duct or grille connecting a room with a door that closes to a central hallway return.
Lesson 29, Air Distribution Systems, Ducts, Returns and Filters - Transfer fluid
- The fluid an indirect system heats, chosen not to freeze at normal outside temperatures; it may not be toxic or flammable.
Lesson 27B, Alternative Energy Systems: Solar PV, Wind and Solar Water Heating - Transfer switch
- A switch that separates the house wiring from the utility grid and feeds selected branch circuits from a generator.
Lesson 27A, Smoke and Carbon Monoxide Alarms, Load Controllers and Generators - Transite
- A brand name often used for asbestos vent material.
Lesson 32D, Oil Vent Systems - Transition cement
- A product that joins ABS and PVC through a fitting of either type; model codes approve it only at the building drain to building sewer connection.
Lesson 37A, DWV Rules and Pipe Materials - Transition duct
- The duct, usually flexible, that joins a clothes dryer to its exhaust duct.
Lesson 16B, Dryer, Kitchen and Bathroom Exhaust - Transom window
- A rectangular window over a door, usually fixed.
Lesson 5B, Windows, Window Flashing, Glazing, Window Wells, Escape Openings and Fall Protection - Trap
- 1. A section of condensate pipe near the evaporator coil, recommended by many manufacturers, installed level so it does not drain.
Lesson 28C, Cooling Systems: Condensate, Line Sets and Thermostats - 2. A fitting, or part of a fixture, that holds a water seal against sewer gas.
Lesson 34A, Plumbing Scope and Plumbing Terms - 3. A fitting that holds a water seal to keep sewer gases out of the house.
Lesson 38A, Traps and Fixture Drains - Trap arm
- Another name for the fixture drain.
Lesson 38A, Traps and Fixture Drains - Trap cleanout plug
- A plug at the bottom of some traps.
Lesson 38A, Traps and Fixture Drains - Trap inlet
- The end of a trap that receives drainage from the fixture.
Lesson 35C, Sinks - Trap primer
- 1. A device and pipe that supply water to keep a trap's seal.
Lesson 34A, Plumbing Scope and Plumbing Terms - 2. A device that adds a small amount of water to a floor drain trap on a regular basis.
Lesson 35E, Standpipes, Floor Drains and Backflow Prevention - Trap water seal
- The water held in a trap, which keeps sewer gas out of the house.
Lesson 35E, Standpipes, Floor Drains and Backflow Prevention - Trash compactor
- An appliance that reduces the volume of household refuse at a ratio of around 4:1 or 5:1.
Lesson 41B, Microwave Ovens, Exhaust Hoods, Disposers, Trash Compactors, Refrigerators and Freezers - Travertine
- A type of limestone used for stone tile.
Lesson 17B, Interior Doors and Floor Coverings - Tray ceiling
- A flat ceiling set higher than the tops of the full-height walls.
Lesson 11A, Structural Scope and Terms - Tread
- The horizontal surface of a stair step.
Lesson 6B, Deck Materials, Flashing, Ledger Attachment and Deck Stairs - Treads
- The horizontal surfaces of a stairway, often called steps.
Lesson 18A, Stairs, Ramps, Handrails and Guards - Trier of fact
- The judge in a bench trial or the jury in a jury trial.
Lesson 21A, Business Law, Claims and Liability - Trim (molding)
- Material that conceals gaps between components and improves how rooms look.
Lesson 17A, Interior Walls, Ceilings, Drywall, Plaster and Trim - Trimmer joists
- Two joists fastened together along each side of a floor opening to form a beam.
Lesson 12A, Floor Framing, Spans, Bearing, Notching and Boring - Trip lever (flush arm)
- The arm that pulls the chain to lift the flush valve.
Lesson 35D, Toilets and Bidets - Trolley
- The opener part that travels along the rail and carries the drive mechanism.
Lesson 7, Garage Vehicle Doors and Operators - Tub/shower
- A bathtub that also has a shower head.
Lesson 35B, Showers and Tub/Showers - Tubular skylight (tubular daylighting device)
- A round dome skylight that transmits light through a reflective tube.
Lesson 10B, Skylights - Tuck pointing (repointing)
- A masonry repair in which new mortar replaces absent and damaged mortar.
Lesson 12E, CMU, Brick, ICF, SIPs and Uncommon Wall Materials - Turbine (whirlybird)
- An active roof ventilation cover whose louvers rotate in the wind and draw air from the attic.
Lesson 16C, Attic Ventilation and Closed Attics - Tutorial
- An introduction to the computerized testing system, offered before the examination, that does not reduce the four hours allotted.
Lesson 43, Scheduling, Taking and Passing the NHIE - Two component system
- Roof to wall flashing made up of base flashing and counterflashing.
Lesson 10A, Roof Flashing: Penetrations, Sidewalls and Headwalls - Two pipe system
- 1. A layout that gives each device a supply pipe connection and a return pipe connection.
Lesson 33B, Hot Water Heating Systems - 2. A steam distribution type that brings steam into each device at one side and takes water out at the other.
Lesson 33C, Steam Heating Systems and Distribution Piping - 3. An oil supply arrangement with a supply line and a return line, which gives air and excess oil a path back to the tank.
Lesson 38I, Oil Supply, Valves, Filters and Tanks - Two-coat cement stucco
- Cement stucco for masonry walls, applied without lath, a scratch coat, or a water-resistive barrier.
Lesson 4B, Fiber Cement, Hardboard, Insulbrick, Stucco, EIFS, Vinyl, Wood and Wood Structural Panel Siding - Two-piece toilet
- A toilet with a separate tank and bowl.
Lesson 35D, Toilets and Bidets - Type B vent
- 1. A manufactured vent pipe that may be used in most Category I vent and vent connector applications.
Lesson 32A, Category I Gas Vent Systems and Vent Defects - 2. A vent for gas-burning appliances, not rated for the heat of burning oil.
Lesson 32D, Oil Vent Systems - 3. A listed appliance vent for gas.
Lesson 39B, Combustion Air, Masonry Chimney Construction, Liners, Flue Area and Defects - Type BW vent
- An oval-shaped Type B vent, used for most gas wall furnaces where the vent runs inside a wall cavity.
Lesson 31B, Floor and Wall Furnaces, Room Heaters and Unvented Appliances - Type K
- A copper tubing wall thickness, heavier than Type L, marked with green labels; copper gas tubing should be Type K or Type L.
Lesson 38F, Gas Pipe Materials: Black Steel, Copper and CSST - Type L
- A copper tubing wall thickness, lighter than Type K, marked with a blue label; copper gas tubing should be Type K or Type L.
Lesson 38F, Gas Pipe Materials: Black Steel, Copper and CSST - Type L and Type D fuses
- Fuse sub-types with a short time delay before opening.
Lesson 24B, Overcurrent Protection, GFCI and AFCI - Type L vent
- 1. A manufactured vent for oil-burning appliances that may serve as a vent or vent connector, and is unusual on gas because it costs more.
Lesson 32A, Category I Gas Vent Systems and Vent Defects - 2. A manufactured vent that may serve as the vent or the vent connector of an oil-fired appliance.
Lesson 32D, Oil Vent Systems - 3. A listed appliance vent for oil.
Lesson 39B, Combustion Air, Masonry Chimney Construction, Liners, Flue Area and Defects - Type S base fuse
- A fuse with a different base size for each rating; adapters fit it to Edison base holders.
Lesson 24B, Overcurrent Protection, GFCI and AFCI - Type W fuse
- A fuse sub-type that opens almost immediately when its rated current limit is exceeded.
Lesson 24B, Overcurrent Protection, GFCI and AFCI - Type X drywall
- 1. Drywall with additional fire-resistant materials, used in fire-rated assemblies.
Lesson 17A, Interior Walls, Ceilings, Drywall, Plaster and Trim - 2. Drywall made with added fire-resistant materials for use in fire-rated assemblies.
Lesson 42, Life Safety Systems: Egress, Fire Separation, Alarms and Sprinklers
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