Cost-plus work tracked by men, hours, equipment, and material on a signed ticket the daily must backIn: Construction daily report guide
T and P relief
Temperature-and-pressure relief valve, the safety valve on a water heater or hot-water vesselIn: Plumbing valve types
T&M
Time and material; out-of-scope work billed on documented labor, equipment, and material rather than a fixed price, and flagged before it is performedIn: Field leadership and the foreman role
The maximum surface temperature class of equipment (T1 450 C to T6 85 C), which must stay below the material's autoignition temperatureIn: Hazardous classified locations
T-joint
The three-layer point where two seams cross, the highest-risk spot on a field seamIn: Single-ply seam QA
T-rating
Time before the unexposed side rises ~325 degrees F (181 degrees C); governs floor penetrations and combustibles against the far sideIn: Cabling pathways and firestop
The list in 1926.1153 pairing common tasks with specified water or vacuum controls; followed fully, it exempts you from air monitoringIn: Silica exposure control program
Table 1 / Table 4 / Table 5
Chapter 9 tables for the percent fill, the conduit dimensions and allowable areas, and the conductor areasIn: Conduit fill, NEC Chapter 9
A fixed production beat at which trades flow through zones like a train, each finishing its zone and handing off on the same intervalIn: Lean construction field guide
Tan-delta
Dissipation factor, the share of applied voltage lost as heat in the insulation, a diagnostic of overall insulation conditionIn: MV cable termination and testing
Tank lining vs exterior coating
The interior immersion film in contact with the product, versus the exterior coating that fights corrosion and UVIn: Tank coating and lining
Tankless / on-demand
A heater that makes hot water as it flows, sized by flow at the rise, with no stored massIn: Water heater types
Tap conductor
A conductor connected to a feeder with no overcurrent device at the connection point, smaller than the feeder device protects at its ampacityIn: Feeder tap rules, NEC 240.21
A tapered joint meets factory long edges in a recess that finishes flush; a butt joint meets cut ends with no recess and finishes proud, so it is harder to hideIn: Drywall and gypsum board finishing
Tapping saddle / sleeve
A saddle clamps the corp to the main for small taps; a tapping sleeve and valve carries a wet tap larger than about 2 in on a live mainIn: Water service and meter tap guide
Anything the tree could hit if it fails: people, structures, vehicles, roads, utilities; occupancy sets how often it is presentIn: Tree risk assessment
Tarp battens / furring strips
Wood strips, commonly 2x4 or 1x4, that wrap and sandwich the tarp edges and are fastened into sound decking to anchor against windIn: Emergency board-up and tarping
Task tuning / trim
High-end trim caps the maximum for savings; low-end trim raises the minimum above the flicker floorIn: Lighting controls and dimming
TBB
Telecommunications bonding backbone, the conductor from the PBB to the SBBs, sized by length, minimum 6 AWGIn: Data center grounding and SRG
The log-log plot of tripping time against fault current; the coordination study plots every device in a path on one chartIn: Coordination study field guide
TCDD / TCCF / TCOS
Uptime certification of design documents, constructed facility, and operational sustainabilityIn: Data center tier classification
TCO
Total cost of ownership: amortized capex plus operating cost over the asset life, usually expressed per MWIn: Data center TCO cost model
Total effective length, the longest supply run plus the longest return run, with each fitting counted as its equivalent length of straight ductIn: Manual D duct design field guide
Telematics
GPS and sensor data on how a vehicle is driven, including speed, hard braking, cornering, and location, used for driver scoringIn: Fleet and driver safety program
Temp power
Temporary power, the electrical system that runs a construction site before the permanent service is energizedIn: Temporary power field guide
Temperature clamp
A pipe-mounted thermistor or thermocouple; accuracy and insulation from ambient air decide the readingIn: Refrigerant charging field guide
Temperature coefficient (beta)
How much Voc changes per degree of cell temperature, from the module datasheetIn: PV system wiring (NEC 690)
Temperature mapping
A color map of mat surface temperature from the infrared sensor, used to keep rolling in the window and find cold spotsIn: Intelligent compaction for asphalt
Engineered bracing or support for a structure that has lost capacity, designed and called for by a structural engineerIn: Emergency board-up and tarping
Tenant improvement (TI) / fit-out
The construction that turns a base-building shell into a finished space for a specific tenantIn: Tenant improvement fit-out
A helical pier loaded in uplift, where the plates bear on the soil above them, used for guy anchors, solar tie-downs, and retaining-wall tiebacks.In: Helical piers and screw piles
A poured composite floor of decorative stone or glass chips set in a matrix, ground and polished to expose the chipsIn: Terrazzo flooring install and polish
Terrestrial vs mobile / SLAM
Terrestrial is the high-accuracy tripod scanner, setup by setup; mobile / SLAM is the fast lower-accuracy walk-through that tracks its own motionIn: Reality capture and scan-to-BIM
Tertiary treatment
Filtration and disinfection after primary and secondary treatment, the common reclaimed standardIn: Reclaimed water and purple pipe
The point right after the job when the customer has just seen the finished work and is most satisfied; the best time to ask for a reviewIn: Customer communication and reviews
An inspection using a camera that maps surface temperature, revealing moisture, faults, and hot spots a visual camera cannot see.In: Drone inspection field guide
Thermal / temperature segregation
Temperature difference across the mat as placed, leaving cold spots that compact poorlyIn: Asphalt segregation
Thermal backfill
Fluidized thermal backfill or thermal sand engineered to hold a low, stable RHO around the bank, replacing native spoilIn: Concrete-encased duct bank field guide
Thermal break
A low-conductivity barrier (polyamide or poured-and-debridged resin) in the aluminum frame that cuts heat flow and stops the frame sweating.In: Curtain wall and glazing
Thermal bridge
A path, like a bare metal hanger, that shorts heat past the insulation and sweats or corrodes on cold serviceIn: Pipe insulation field guide
Thermal bridging
Heat conducting around the insulation through framing, so the whole-assembly R falls below the cavity RIn: Building insulation and air sealing
Cold lumps or streaks in the mat from uneven load temperature, a low-density defect a material transfer vehicle preventsIn: Cold-weather asphalt paving
Thermal-stress cracking
A pane cracking from a temperature difference between its hot center and cooler framed edge, the main film-related break riskIn: Commercial window film
ASNT SNT-TC-1A qualification tiers, Level I to scan, Level II to interpret and judge severity, Level III to write proceduresIn: Infrared thermography field guide
Thermographer qualification
Recognized training and certification in infrared interpretation, commonly Level I and Level II under ASNT SNT-TC-1A.In: Drone inspection field guide
IR imaging that finds hot spots and dead modules and strings, and current-voltage tracing that confirms module or string health electricallyIn: Solar PV O&M field guide
The structure that holds the base oil, such as lithium, lithium-complex, or polyurea; mixing incompatible types fails the greaseIn: Motor bearings and shaft grounding
Thickness / DFT
The applied depth that delivers the rating; dry film thickness is the intumescent equivalentIn: Structural fireproofing
Thin / ultra-thin overlay
A new HMA wearing course about 1 to 1.5 in or less, a functional surface treatment that adds little structureIn: Pavement preservation treatments
Thinset mortar / coverage
The cement mortar bonding tile to the substrate; coverage is the share of the tile back in contact with mortar, commonly 80 percent dry and 95 percent wet.In: Ceramic and porcelain tile installation
Three points of contact
Two hands and one foot, or two feet and one hand, on the ladder at all times while climbingIn: Portable ladder safety
Three-coat / lath
Scratch, brown, and finish coats keyed into metal lath over the WRBIn: Stucco and EIFS
Three-phase inspection
The preparatory, initial, and follow-up control model from the US Army Corps of EngineersIn: Quality control and the ITP
Three-sided adhesion
Sealant bonded to both walls and the bottom, which cannot stretch and tears when the joint opensIn: Joint sealant replacement
A valve built to regulate flow at intermediate positions, such as a globeIn: Plumbing valve types
Through vs membrane penetration
Through breaches both sides of the assembly; membrane breaches one side; each has its own tested systemIn: Cabling pathways and firestop
Through-bolt cleat board-up
Securing method with plywood outside and 2x4 cleats inside, clamped together by carriage bolts through the opening, used where security matters or no frame remainsIn: Emergency board-up and tarping
Through-fastened vs standing seam
Screw-down panels fastened through the face into the secondary, versus concealed-clip panels with the seam locked above the water lineIn: Metal building erection
Through-hardware
An eye bolt or amon eye run fully through the stem and held with a washer and nut, bearing across the woodIn: Tree cabling and bracing
The landlord's capped contribution to the fit-out, stated in dollars per square foot, usually paid as a reimbursementIn: Tenant improvement fit-out
TIA-222 loading analysis
The engineer's calculation under TIA-222 of whether a tower can carry specific equipment under code wind and ice loadsIn: Cell tower and antenna install
TIA-606
The administration standard for labeling and records, requiring an identifier at each cable endIn: Data center rack cable management
A drilled, grouted, post-tensioned tendon anchored in soil or rock behind the wall to hold it without bracing inside the hole.In: Excavation shoring field guide
The EPA's most stringent engine emissions tier, typically requiring SCR and a DPF on large enginesIn: Generator emissions and permitting
Tiered plan
A good-better-best ladder of two or three plans at rising price and inclusion, matching price to what each customer will payIn: Service agreements and recurring revenue
The shape of the tile, flat, low, or high (S-tile, barrel, mission), interlocking or overlapping, which sets the look and the water channelIn: Tile roof installation
Tilt-up
Wall construction where panels are cast flat on the floor slab and lifted upright by crane into placeIn: Tilt-up bracing and erection
Time and materials (T&M)
Pricing by actual labor, material, and equipment against agreed rates, used when scope cannot be taken off in advanceIn: Field change order takeoff
Time to hire
Days from a seat opening to the new hire's start date; long times signal a dry pipelineIn: Hiring and onboarding techs
The distance from the finished wall to the center of the closet flange, commonly 12 in, with 10 in and 14 in alternatesIn: Fixture rough-in and setting guide
Tolerance
The allowed deviation of the built work from its true location, set by the spec and the trade standard, not by the instrumentIn: Construction layout
Tolerance (+/- 10%)
The acceptable band around design airflow, commonly plus or minus 10 percent at outlets, set by the specIn: Air balancing report field guide
Cutting stems back to stubs with no regard for laterals, which causes decay and weak watersprout regrowthIn: Tree pruning and maintenance
Torque-seal
A marking compound striped across a torqued screw and lug to show if it later movedIn: Splices and terminations
Torque-to-capacity / Kt
The empirical correlation Qult equals Kt times final installation torque; Kt is the manufacturer's and engineer's factor for the specific shaft and load direction.In: Helical piers and screw piles
Torr / micron
Absolute deep-vacuum units; 1 torr is 1 mm of mercury, 1 micron is one-thousandth of a torrIn: Lab and process vacuum systems
Torsion winds on a shaft above the door; extension stretches along the side tracks; both store the door's weight as energyIn: Overhead door and dock leveler field guide
Total air
The full airflow the fan delivers, measured by a pitot traverse in the main and set before branch balancingIn: Air balancing report field guide
A rotating enthalpy wheel that transfers both heat and moisture between the exhaust and the entering outdoor airIn: DOAS field guide
Total facility energy
All energy crossing the data center boundary: IT load plus cooling, power losses, lighting, and building systemsIn: Data center PUE and energy efficiency
Slip an activity can take without moving the finish (total) or the next activity (free)In: Project scheduling
Total flooding
Filling an entire sealed enclosure with agent to a design concentration, rather than aiming at a single objectIn: Data center fire suppression compared
TPO
Thermoplastic polyolefin, a white, heat-weldable, reflective single-ply membrane at a moderate costIn: TPO vs EPDM vs PVC
TPO / PVC
Thermoplastic single-ply membranes whose seams are hot-air welded into one fused materialIn: Single-ply seam QA
The thin polyurethane or latex surface of binder and rubber granules laid over the baseIn: Running track surfacing
Track-out
Mud carried onto the public road by tires, controlled by the stabilized construction entrance, and a highly visible violationIn: Erosion control and SWPPP
Tracker
A single- or dual-axis mount that follows the sun to add production, with a motor, drive, bearings, and a controller that wind-stows in high windIn: Solar PV O&M field guide
Traction hangs the car on ropes over a sheave with a counterweight (mid to high-rise); hydraulic uses a pump and a jack to push the car from below (low-rise)In: Elevator modernization and maintenance
The pump, usually with a standby, that moves fuel from the bulk tank to the day tank on a level controlIn: Generator fuel system and day tank
Transfer switch (MTS / ATS)
A device that moves the load between utility and generator, breaking the utility; manual on a portable set, automatic on a standby setIn: Generator interlock and backfeed safety
A conductor on the secondary side of a transformer, unprotected at its supply because the primary device cannot protect it at secondary ampacity; governed by 240.21(C)In: Feeder tap rules, NEC 240.21
Transition zone
The band across the middle of the country where neither cool- nor warm-season grass is fully adaptedIn: Turfgrass selection
Moving an established tree, ball and all, from one location to another, as opposed to planting nursery stockIn: Tree transplanting
Transport time
The time for smoke to travel from a sampling hole to the detector, kept under the code maximum, commonly 120 seconds in the AmericasIn: Aspirating smoke detection
The code requirement to keep an evaporation-prone trap charged, met by a primer, a barrier device, or a deep-seal arrangementIn: Trap primer field guide
Trap weir
The top of the trap outlet, the level water rises to before it spills toward the drain; the AAV mounts above itIn: AAV and island vent guide
TRAQ levels
ISA assessment depths: Level 1 limited visual, Level 2 basic 360-degree ground inspection, Level 3 advanced with toolsIn: Tree risk assessment
Travel restraint vs fall arrest
Restraint keeps a worker from reaching the edge so no fall happens; arrest catches a worker after a fall and needs clearance belowIn: Rooftop permanent fall protection
Traverse
A grid of velocity readings across a duct, averaged to get true airflow; log-Tchebycheff spacing is the accurate methodIn: Air balancing report field guide
Tray fill
The portion of the tray cross-section the cable may occupy, limited by NEC 392.22In: Cable tray field guide
Treated-lumber fastener corrosion
The galvanic attack copper-based preservatives drive on regular and electro-galvanized steel, requiring hot-dip galvanized or stainless metalIn: Deck construction field guide
Tree guard
A cylinder or wrap around a trunk protecting young bark from rabbit and vole girdling and deer rub; removed before it girdles the growing treeIn: Deer and wildlife protection
Tree risk assessment
The systematic evaluation of likelihood of failure, likelihood of impacting a target, and consequence, combined into a risk ratingIn: Tree risk assessment
Tree spade
A hydraulic machine whose blades cut and lift a tree and its ball in one cone-shaped pieceIn: Tree transplanting
Tremie
A smooth steel pipe, commonly 10 to 12 in, used to place concrete from the bottom up under slurry or water without contaminationIn: Drilled piers and caissons
Trial weld
A daily and per-condition test seam pulled by hand to confirm welder settings before productionIn: Single-ply seam QA
Trigger depth
The snow accumulation that starts a plow push, commonly 1 to 2 in, set by the contractIn: Snow and ice management
Trim and respond
A reset method that lowers a setpoint at a fixed rate, then raises it in response to requests from zones that cannot keep upIn: VAV box commissioning field guide
Air pressure in the system at the instant the valve unseats, compared against the manufacturer's expected trip pointIn: Dry-pipe and pre-action trip test
Triple evacuation
Pulling vacuum, breaking it with dry nitrogen, and repeating three times to dry a wet or contaminated systemIn: Refrigerant evacuation field guide
OSHA recordable rates per 200,000 hours; TRIR counts all recordables, DART counts cases with days away, restricted duty, or transferIn: Subcontractor prequalification and bid lists
Trowel
Closes and densifies the set surface; a steel blade pitched steeper each passIn: Flatwork finishing sequence
TRT
Thermal response test, an in-situ measurement of formation thermal conductivity for sizing large loop fieldsIn: Geothermal heat pump field guide
The proof packet handed to the owner at acceptance of a scope or system, the commissioning record set rolled up with the punch closeout and the signoffsIn: Proof packet assembly
Turnover rate
The hours to circulate a volume equal to the whole pool through the filter once; set by the health codeIn: Pool and spa mechanical systems
Total volatile organic compounds, a single proxy index for a mix of gaseous organics, not a measurement of any one chemicalIn: IAQ monitoring and sensors field guide
Cooling that removes heat by boiling a dielectric fluid at the heat source and condensing the vapor, carrying heat as latent heatIn: Two-phase cooling
Two-phase immersion
Immersion where the fluid boils at the chip and condenses on a coil, carrying heat as latent heat of vaporization in a sealed tankIn: Immersion cooling acceptance
NFPA 110 ratings: Type is restore time in seconds, Class is on-site run time in hours, Level is criticalityIn: Emergency and standby power systems
Type 1 / 2 / 3
SPD classes by install location: line side of the service, load side at panels, and point of useIn: SPD installation field guide
Type 1 splice
A mechanical splice required to develop at least 125 percent of the bar's specified yield strength, per ACI 318In: Mechanical splices and couplers
Type 1 to 4
IEEE PoE classes: af (15.4 W), at (30 W), and bt Type 3 (60 W) and Type 4 (90 W) at the sourceIn: PoE voltage drop and heat
Type 2 splice
A splice that meets Type 1 and also develops the bar's specified tensile strength, required in seismic yielding regionsIn: Mechanical splices and couplers
Type 4
Component SPD or assembly built into equipment by the manufacturer, not field-addedIn: SPD installation field guide
Type A / B / C cable
How an array cable is wired internally: straight-through, reversed, or pair-flipped; the cable, not the channelIn: MPO/MTP polarity methods
Type A / B / C tube
Ballast-compatible, ballast-bypass (direct-wire line voltage), and external-LED-driver tube wiring typesIn: LED lighting retrofit
Type I handles grease over cooking equipment and is fire-protection equipment under NFPA 96; Type II handles heat and steam only, over dish and oven equipment, with no grease ductIn: Kitchen equipment install field guide
Copper wall thicknesses under ASTM B88, thickest to thinnest, same outside diameterIn: PEX, copper, and CPVC methods
Type L / K copper
Copper tube wall thicknesses for medical gas, cleaned for oxygen service, commonly to ASTM B819In: Medical gas piping field guide
Type X (fire-rated)
A 5/8 in board with a core reinforced to resist fire longer, used in tested fire-rated assemblies; Type C goes further and is not interchangeableIn: Drywall and gypsum board finishing