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Term Definition

A type of sill construction used in balloon framing in which the header joist is placed inside the studs and is butted by the floor joists.


A fabric upon which colored threads are woven by hand to produce a design.


Precast concrete or metal structural members in the shape of the letter T.

Temper Designation

A specification of the temper or metallurgical condition of an aluminum alloy.


Measurement of the intensity (not quantity) of heat. The Fahrenheit (°F) scale places the freezing point of water at 32° and the boiling point at 212°. The Centigrade or Celsius (°C) scale, used by most countries and in scientific work, places the freezing point of water at 0° and the boiling point at 100°. On the Kelvin (K) scale, the unit of measurement equals the Celsius degree and measurement begins at absolute zero 0° (-273°C).

Tempered Glass

Heat-treated glass that has great resistance to breakage and increased toughness.


The reheating of hardened steel to decrease hardness and increase toughness.

Tempering Glass

A process used to strengthen glass by raising the temperature of the glass to near the softening point and then blowing jets of cold air on both sides suddenly to chill it and create surface tension in the glass.


A steel bar or cable in prestressed concrete used to impart stress in the concrete.

Tensile Bond Strength

The ability of a mortar to resist forces tending to pull the masonry apart.

Tensile Strength

Maximum tensile stress that can be developed in a given material under axial tensile loading. Also the measure of a material's ability to withstand stretching.

Tensile Stress

The stress per unit area of the cross-section of a material that resists elongation.


Force that tends to pull the particles of a body apart.


A hard unglazed clay tile used for ornamental work.


A finish-floor material made up of concrete and an aggregate of marble chips that after curing is ground smooth and polished.

Texture Plaster

A finish plaster used to produce rough, textured finished surfaces.

Thermal Break

Material with a low thermal conductivity that is inserted between materials, such as metal with high thermal conductivity, to slow the passage of cold or heat through the highly conductive material.

Thermal Bridge

A thermal conducting material that conducts heat through an insulated assembly of materials.

Thermal Conductance (C)

Thermal conductance is the same as thermal conductivity except it is based on a specified thickness of material rather than on one inch as used for conductivity.

Thermal Conduction

The process of heat transfer through a solid by transmitting kinetic energy from one molecule to the next.

Thermal Conductivity (k)

The rate of heat flow through one square foot of Btu per hour when a temperature difference of one degree Fahrenheit is maintained between the two surfaces.

Thermal Convection

Heat transmission by the circulation of a liquid or heated air or gas.

Thermal Expansion

All materials expand and contract to some extent with changes in temperature. The Thermal Coefficient of Linear Expansion is expressed in "Inches Per Inch Per Degree Fahrenheit." Example: gypsum board has a coefficient of 9.0 x 10-6 in. per in. per °F. This means that with an increase in temperature of 50°, a gypsum board wall 100 ft. in length will have a linear expansion of .54" or an excess of 1/2". The expansion characteristics of some other building materials are more pronounced; a 50° temperature increase would produce expansion in a 100' length of approx. 3/4" in aluminum, 3/8" in steel and 1/2" in concrete.

Thermal Insulation

A material that has a high resistance to heat flow.

Thermal Properties

The behaviour of a material when subjected to a change in termperature.

Thermal Radiation

The transmission of heat from a hot surface to a cool one by means of electromagnetic waves.

Thermal Resistance (R)

Resistance of a material or assembly to the flow of heat. It is the reciprocal of the heat transfer coefficient: (1/C, or 1/U)

For insulating purposes, low "C" and "U" values and high "R" values are the most desirable.


A process in which heated plastic sheets are made to assume the contour of a mold by using the force of air pressure, vacuum, or mechanical stretching.


Plastics that soften by heating and reharden when cooled without changing the chemical composition.

Thermosetting Plastics

Cured plastics that are chemically cross-linked and when heated will not soften but will be degraded.


A temperature-sensitive instrument that controls the flow of electricity to units used to heat and cools spaces in a building.


Raised member at the floor within the door jamb. Its purpose is to provide a divider between dissimilar flooring materials or serve as a thermal, sound or water barrier.

Through-penetration Fire Stop

A system for sealing through-penetrations in fire-resistant floors, walls and ceilings.


Through-penetration, or "poke-through" openings as they are sometimes called, are holes that penetrate an entire floor or wall assembly to allow the passage of piping, ducts, conduit, cable trays, electrical cables, communications wiring, etc.


The horizontal or vertical distance an airstream travels after leaving the air outlet before it loses velocity.

Tieback Anchors

Steel anchors grouted into holes drilled in the excavation wall to hold the sheeting, thus reducing the number of braces required.


Wood structural members having a minimum m thickness of 6 inches (140 mm).

Timber Joinery

The joining of structural wood members using wood joints, such as the mortise and tenon.

Time-Temperature Curve

Rate of rise of temperature in a fire-testing furnace.


Method of fastening two boards together as in a "T" by driving nails into the board that forms the stem of the "T" at an angle so they enter the other board and cross each other.


The permissible deviation from a given dimension or the acceptable variation in size from the given dimension.

Tongue-and-Groove Joint

Joint where the projection or "tongue" of one member engages the mating groove of the adjacent member to minimize relative deflection and air infiltration; widely used in sheathing, flooring and paneling. Tongues may be in "V," round or square shapes.


The final coat of paint.


A twisting or rotating action.

Torsion Strength

The maximum stress a material will withstand before fracturing under a twisting force.

Torsion Test

A test used to ascertain the behavior of materials subject to torsion.


A measure of the ability of a material to absorb energy from a blow or shock without fracturing.


An electrical device used to convert an incoming electric current from one voltage to another voltage.

Transmission Loss (TL)

Essentially the amount, in decibels, by which sound power is attenuated by passing from one side of a structure to the other. TL is independent of the rooms on each side of the structure and theoretically independent of the area and edge conditions of the structure.


A device used to maintain a water seal against sewer gases that back up the waste pipe. Usually, each fixture has a trap.


Horizontal plane or surface of a stair step.


Double joists or rafters framing the opening of a stairway well, dormer opening, etc.


Producing a final smooth finish on freshly poured concrete with a steel-bladed tool after the concrete has been floated.


Open, lightweight framework of members, usually designed to replace a large beam where spans are great.

Truss Plate

A steel plate used to strengthen the joints in truss assemblies.

Truss-Framed System

An assembled truss uint made up of a floor truss, wall stud, and a roof truss.

Tufted Construction

Carpet formed by stitching the pile yarn through the backing material.


Warping in which one or more corners of a piece o wood twist out of the plane of the piece.

Two-Way Concrete Joist System

Floor and roof construction that has two perpendicular systems of parallel intersecting joists.

Two-Way Flat Plate

Reinforced concrete construction in which the main reinforcement runs in two directions and both surfaces are flat planes and it is supported by columns.

Two-Way Flat Slab

Reinforced concrete floor or roof construction in which a two-way flat plate is supported by columns with drop panels or column capitals.

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