Tonne

Ton

The exposed portion of strip shingles defined by cutouts.

Whitish powder applied at the factory to the surface of some roofing materials (e.g., vulcanized EPDM membranes), used as a release agent to prevent adhesion of the membrane to itself.

A tapered insulation strip used to (1) Elevate and slope the roof at the perimeter and at curbs that extend through a roof; (2) Provide a gradual transition from one layer of insulation to another.

(1) The technique of sealing a joint between metal and the built up roof membrane with one or two plies of felt or fabric and hot applied or cold applied bitumen; (2) The technique of sealing the joint between base flashing and membrane plies or between metal and built-up membrane with one or two plies of felt or fabric and hot or cold applied bitumen; (3) The technique of taping joints between insulation boards or deck panels or units. See STRIPPING or STRIP-FLASHING.

A brown or black bituminous material, liquid or semi solid in consistency, in which the predominating constituents are bitumens obtained as condensates in the processing of coal, petroleum, oil shale, wood, or other organic materials.

Bubbles of moisture vapor encased in a thin film of bitumen, also known as "blackberries".

A felt that has been saturated with refined coal-tar. See COAL TAR FELTS.

Removing a failed roof system down to the structural deck.

The removal of all roof system components down to the structural deck, followed by installation of a completely new roof system.

(1) A measure of the stress needed to continue rupturing the elastomeric sheet, usually after a cut has been initiated in the sheet; (2) The load required to tear a material, when the stress is concentrated on a small area of the material by the introduction of a prescribed flaw or notch. Expressed in psi (pounds force) per inch width or kN/m (kilonewton per meter width).

The maximum force required to tear a specimen.

A shingles distortion that may arise when a new roof is applied over an uneven surface.

(1) The ability of the membrane to resist cyclic induced internal and external tensile forces; (2) The ability of a given membrane material to resist "fatigue" and/or other damage (such as loss of elasticity) caused by the alternate stretching and relaxing of the material over a period of time.

(1) The maximum force per unit of original cross section area which the membrane can achieve when it elongates to rupture; (2) The maximum force (longitudinal pulling stress) a material can bear without tearing or breaking apart.

A test in which a specimen is subjected to increasing longitudinal pulling stress until fracture occurs.

The treatment or method of anchoring and/or sealing the free edges of the membrane in a roofing or waterproofing system.

An alloy of lead and tin, used to coat sheets of carbon steel or stainless steel for use as metal roofing sheet.

Low-fired clay, either glazed or unglazed.

A sample of the roof membrane, usually 4" x 40" in size, that is cut from a roof membrane to (a) Determine the weight of the average interply bitumen moppings; (b) diagnose the condition of the existing membrane (e.g., to detect leaks or blisters). NRCA recommends that the test cut procedure NOT be used as a means of determining the quality of a roof system; (2) A sample of the roof, which may contain all components or just the membrane, usually used to diagnose the condition of the exiting membrane, evaluation the type and number of membranes or rates of application such as determine the weight of the average interply bitumen moppings.

A solvent welding solution.

The covering of a roof usually made of straw, reed or natural foliage (palms) bound together to shed water.

An alloy of lead and tin, used to coat sheets of carbon steel or stainless steel for use as metal roofing sheet.

(1) A unit of heat flow that is used for specific thicknesses of material or for materials of combination or composite construction, such as laminated insulation. The formula for thermal conductance is:

C = _________k__________
         THICKNESS IN INCHES

(2) Heat energy in Btu per hour (Btuh) transferred via conductance only through 1-ft2 are of homogeneous material per ?F temperature difference from surface to surface. The unit is Btuh/(ft.2?F) [in metric terms, W/(m2.K)]; (3) The thermal transmission in unit time through unit area of a particular body or assembly having defined surfaces, when unit average temperature difference is established between the surfaces: C=Btu/h_ft__?F;C=(W/m__K.

(1) The heat energy that will be transmitted by conduction through one square foot of 1" thick homogeneous material in one hour when there is a difference of 1? F perpendicularly across the two surfaces of the material. The formula for thermal conductivity is: k = Btu/SQUARE FOOT/ INCH/HOUR/DEGREE FAHRENHEIT. (2) Heat energy (Btuh) transferred via conductance only through a 1-in.-thick 1 ft2 area of homogeneous material per ?F temperature difference from surface to surface. Unit for k is Btuh/(in.2?F).

A visual representation of temperature distribution over a surface area. The image is displayed on a screen, presenting the response to infrared light waves

A material applied to reduce the flow of heat. See INSULATION.

(1) An index of a material's resistance to heat flow; it is the reciprocal of thermal conductivity (k) or thermal conductance (C). The formula for thermal resistance is:

R = 1 or R = 1 or R = THICKNESS IN INCHES
      C            k                             k

(2) Material's resistance to conductive heat flow, in ?F/(Btuh.ft2)--that is, for a 5? F temperature difference surface to surface, 1 Btuh would flow through a 1 ft2 specimen with R = 5; (3) The average temperature difference between two defined surfaces of a particular body or assembly when unit thermal transmission in unit time through unit area is established between the surface. R = ?F h s ft2/Btu (R = K m2/W).

The stress-producing phenomenon resulting from sudden temperature changes in a roof membrane when, for example, a cold rain shower follows brilliant, hot sunshine, which may result in sudden cooling or rapid contraction of the membrane.

Mathematical expression for calculating the theoretical temperature drop required to split a rigidly held membrane test sample under tensile contractive stress.

The tensile or compressive stress experienced by a material due to cooling (or heating) alone.

A visible light record of the display of an infrared camera system via a Polaroid print, 35 mm film, video tape or computer-generated image.

A technique for producing heat "pictures" from the radiant energy emitted from stationary or moving objects without in an way influencing the temperatures of the objects under view. The electronic generation and display of a visible image of an infrared spectrum.

(1) A material which can be reshaped or formed upon the application of heat; PVC or CPE materials are thermoplastics; (2) Changing viscosity under thermal cycle (fluid when heated, solid when cooled); (3) Materials that soften when heated and harden when cooled. This process can be repeated provided that the material is not heated above the point at which decomposition occurs.

A blend of polypropylene and ethylene-propylene polymers. Colorant, flame retardants, ultraviolet absorbers and other proprietary substances which may be blended with the TPO to achieve the desired properties. The membrane may or may not be reinforced.

A material that solidifies or "sets" irreversibly when heated. This property is usually associated with crosslinking of the molecules induced by heat or radiation.

(1) A material which cannot be reshaped or formed by heating; cured synthetic rubber sheet materials (EPDM, Butyl, etc.) are thermosets; (2) Hardening permanently when heated, owing to cross linking of polymeric resins into a rigid matrix.

Abbreviation for tetrahydrofuran, a solvent used to weld some thermoplastic materials together, such as PVC.

The number of threads per inch in each direction, with the warp mentioned first, and the fill second (e.g., a thread of 20 x 10 means 20 threads per inch [25.4 mm] in the warp and 10 threads per inch [25.4mm] in the fill direction).

See LAMINATED SHINGLES.

(1) A water-resistant membrane or material assembly extending through a wall and its cavities, positioned to direct any water entering the top of the wall to the exterior; (2) Water-resistant membrane or material assembly extending through a wall's horizontal cross section and designed to direct water flow through the wall toward the exterior; (3) A water-resistant material, which may be metal or membrane, extending through a wall and its cavities, positioned to direct water entering the top of the wall or cavity to the exterior, usually through weep holes.

(In roofing and waterproofing). The transitional seal used to terminate a roofing or waterproofing application at the top or bottom of flashings or by forming a watertight seal with the substrate, membrane or adjacent roofing or waterproofing system.

Thermal Insulation Manufacturers Association

A two-piece assembly consisting of a threaded bolt and an expanding clip that can fit through a drilled hole. The clip can spring outward to provide anchorage form the blind side.

One of the oldest types of dimensional structural wood used as roof decking. The sides are cut with convex and concave grooves so adjacent planks may join in alignment with each other to form a uniform roof deck.

Tri-polymer alloy.

See THERMOPLASTIC OLEFIN.

Siding containing asbestos.

(1) Troweling mortar into a joint after masonry units are laid; (2) Final treatment of joints in cut stonework. Mortar or a putty like filler is forced into the joint after the stone is set; (3) The process of removing deteriorated mortar from an existing masonry joint and troweling new mortar or other filler into the joint.

A top shingle with sections cut away creating "tabs" of the remaining shingle. This top portion is then laminated to a half shingle which backs the exposed sections. The total effect is multi-layered, dimensional appearance. Also called "Laminate".