Glossary- Metal Components, Building and
Construction Terminology

Accessory – An additional product that adds to a solid sheeted roof / wall, such as, Louver, Walk Door, Roof Curb, etc.

Approval Drawings – Drawings approved by the buyer that affirm that the manufacturer has correctly interpreted the contract

Architectural Panel – Panel with special attention given to its appearance and primary purpose for aesthetic enhancement.

Auxiliary Loads – All specified dynamic live loads other than the basic design loads that the building must safely withstand such as cranes, material handling systems, machinery, elevators, vehicles, and impact loads.

Bracing – Used to resist lateral wind forces imposed on the framing system, may be an angle, cee, cable or flat strapping.

Building Code – Adopted regulations established by a recognized agency or authority describing design loads, procedures and construction details for structures, applying to a designated political jurisdiction (city, county or state).

Capillary Action – Action causing movement of liquids when in contact with two adjacent surfaces such as panel side-lap.

Cold-Formed – The process of forming sheet steel into desired shapes through a series of rollers in a rolling mill or by bending at ambient temperature. Shapes are such as angles, channels, “C” sections, and “Z” sections.

Condensation – The conversion of water vapor or other gas to liquid as the temperature drops.

Dead Load – Non-moving rooftop or suspended loads, such as mechanical equipment or ductwork, air conditioning units, fire sprinkler systems and the roof deck itself.

Deflection – Displacement of a structural member relative to its supports due to applied loads. Can be horizontal or vertical.

Design Loads – Loads specified in the contract documents, which the metal roofing system is designed to safely resist.

Diaphragm Action – Resistance to racking offered by the covering system, fasteners, and secondary framing.

Drift Load – The positive acting load that is created due to accumulation and drifting of snowfall. Typically located at valleys, roof-to-wall conditions and other areas that allow snow to accumulate above its initial snowfall.

Fixed Eave – Condition that has the roof panels fixed at the eave and floating at the peak, allowing thermal movement upward.

Floating Eave – Condition that has the roof panels floating at the eave, allowing for thermal expansion / contraction and are fixed at the ridge.

Galvanized Coating – Typical coating weight for galvanized metal sheet, equates to ounces of zinc per square foot, measured on both the front and back surfaces. Std. coating weights are G-30, G-60, G-90 or G-100.

Galvalume Plus – High quality sheet steel with a corrosion resistant metallic coating of aluminum and zinc.

Ground Snow Load – Weight of snow on the ground for specified recurrence interval exclusive of drifts or sliding snow.

Ice Dam – Build-up of ice that forms a dam on the roof panels, usually along the eave of the building.

Kynar – Finish combines ceramic pigmentation with poly-vinylidene fluoride. This provides a superior, long lasting, color retentive, durable and corrosion resistant feature.

Live Load – Loads on floors and roofs that are produced, during maintenance by workers, equipment, and materials. During the life of the structure by movable objects but not including wind, snow, seismic or dead loads.

Oil Canning – Inherent characteristic of metal panels manufactured with non-interrupted flat areas caused by the expansion and contraction of the metal during outside temperature changes. All panels manufactured from light gauge metal may exhibit oil canning in the broad flat portions or pan, of the panel. It is not considered to be a defect nor does it affect the structural integrity of the metal panels. Oil canning is not cause for rejection.

Panel Creep – Tendency of the transverse dimension of panel to gain in modularity due to spring-out or storage-distortion.

Perforated – In relation to metal construction, refers to panels or sheet metal strips that have been mechanically and uniformly punched with holes in various manners to provide air circulation.

Roll Formed – Specific width metal sheet coil or strip that has been cold-formed into a desired cross section by being inserted and driven through a rolling mill, then a series of roller dies progressively form the panel’s final cross-section.

Silicone-Polyester – A polyester resin merged with a silicone resin intermediate paint finish. Excellent exterior protection and resistance to chemical corrosion and ultra-violet exposure.

Snow Load – A positive acting load imposed on the roofs of buildings due to snow fall.

Striations – Lines that are parallel to the panel ribs, which have a low silhouetted profile. These striations assist in masking any oil canning affects that are in the flat pan of the panel.

Thermal Movement – The expansion / contraction that occurs due to temperature changes.

Thermal Resistance (R Value) – Mean temperature difference between two surfaces of material that induces unit heat flow through the unit area.

Thermal Transmittance (U Factor) – Time rate of heat flow per unit area under steady conditions from the fluid on the warm side of a barrier to the fluid on the cold side, per unit temperature difference between the two fluids.

Vapor Barrier – Material used to stop the flow of vapor or moisture, which prevents condensation from forming on a surface.

Wind Load – Load (MPH / PSF) caused by the wind coming from a horizontal direction

Wind Uplift – Differential negative pressure caused by the deflection of wind at roof edges, roof peaks or obstructions, which will cause a drop in air pressure directly over the roof surface. If wind pressure is allowed to enter underneath the membrane or roof edges, it may cause the membrane to lift up and pull away from the deck.