A
Anchor Clip
A formed aluminum or galvanized steel attachment clip (chair) used for securing 12'-0" coping sections to the top of a parapet wall or curb condition.
Anodizing
A finishing process of coating aluminum by means of electrolytic oxidation, producing a thin layer of aluminum oxide. This protective layer is extremely hard and provides a long term architectural finish (aluminum anodic oxide coating). Available in clear or color applications.
Anodizing, Two-Step Batch
Sometimes referred to as hardcoat or Duranodic finishes, provides the heaviest and most durable anodic color coatings available. Because hardcoat anodizing is produced piece by piece (or batch), it is a more expensive option compared to the coil anodizing process. Color consistencies during a hardcoat run may vary substantially due to the difficulty in controlling submersion time, electrical currents, and the chemical composition of the batch.
Anodizing, Two-Step Coil
This process is the most economical and consistently uniform method of anodizing aluminum. A lower margin for error and reduction in labor costs is obtained through the highly automated coil anodizing process.
B
Balanced System
Condition where intake ventilation at the eaves is equal to exhausted air at the ridge.
Ballast Paver
A cementitious block molded into various sizes, shapes and weights, used to protect roofing systems from the effects of billowing, roof traffic, ultra violet degradation and extreme up-lift pressures created by high wind conditions.
Ballast Stone
Stone or aggregate loose laid over single-ply roofing systems. It is used to hold the roof membrane down on the roof deck preventing billowing effects.
Button Hole
A slightly raised fastening hole located on the vertical face of various Metal-Era waterdam components. Allows the installer to easily locate proper nail spacing through the membrane flashing.
C
Cant Dam
The 45° vertical distance above a roof deck/membrane to the top of a fascia detail, restricting the flow of water over the edge of a roof.
Caulk Cup
A sealant ledge usually located at the top of a termination bar of counter flashing used to receive a bead of waterproofing caulk.
Cleat
A formed metal strip designed to hook into and securely engage the lower most edge of a gravel stop or similar detail; a continuous cleat engages a product along its entire length, fastened 12" o.c.
Condensation
Water vapor in warm air that changes to liquid when it comes into contact with a colder surface.
Coping
The covering piece on top of a wall exposed to the weather. It is usually made of metal, masonry or stone and is sloped to carry off water and is used to waterproof the top of a parapet wall or curb condition.
Counterflashing
A formed metal flashing which provides a watertight seal/termination at the leading edge of a roofing material, usually as the membrane turns up a wall or curb. A 2 pc. counterflashing, (sometimes referred to as reglet counterflashing), can be taken apart and reused to make necessary repairs on the roof.
Coverage
Refers to the number of nailers or surface dimension to be covered by a steel or aluminum sheet metal product.
Cover Plates
Formed metal pieces ranging from 3½" to 8" wide which are installed over the joints of abutting gravel stops, copings, gutter and counterflashings to prevent water entry and maintain joint integrity.
Crazing
Strain marks or elongation of heavy gauge materials as the metal stretches around tight tooling angles. The appearance of slight fractures or cracking of the metal, paint or anodized surface caused by forming.
D
Deck
The surface applied to roof joists or trusses to which the roofing materials are applied.
Downspout
A formed metal tube used to carry water from a roof level, scupper/collector box or gutter system to the ground. Closed downspout is capable of transporting large volumes of water. Open face downspout is used where ice or debris clogging causes potential maintenance problems.
Drip Edge
A sheet metal form on the lower edge of a gravel stop, coping, counterflashing or drain bar which is at 30°, 45° or 60° to keep dripping water from running directly down the face of a building.
Duranodic
Type of anodized finish. See Anodizing.
E
Eave
The part of a sloping roof that overhangs the wall, the part of a roof which projects out from the side wall or the lower edge of the part of a roof that overhangs a wall.
Elbow, 90° & 45°
An angled section of downspout fabricated as an accessory item for downspout direction changes. Available in 90° or 45° versions (standard), in Style A (angled away or perpendicular to the wall), or Style B (angled parallel to the wall).
Electrolytic Action Between Dissimilar Metals
A galvanic action which results in the deterioration of a weaker metal in the presence of an electrolyte, like water, containing small amounts of acid, pollutants, or salt (e.g. impure rain water); for more information, refer to "Modern Application of Sheet Copper in Building Construction", AIA File #12, Copper and Brass Research Association (also known as galvanic reaction).
Embossing
A process which imprints a design into metal coil/sheet by depressing the top and bottom surfaces using a patterned set of rollers (also known as texturing).
Endcap
A welded or quicklocked metal piece used to close off or cap an unfinished end of sheet metal flashing.
Expansion Joint
A gutter accessory item which allows for substantial thermal movement of a gutter system, particularly in large seamless runs where joints are spaced greater than 12'-0" apart.
Extender
A formed steel or aluminum fascia product which provides additional coverage down a building face not furnished by a gravel stop or edge detail. Recommended for use when light gauge materials cannot achieve coverage requirements without compromising strength, flatness or aesthetic considerations.
Extrusion
Aluminum products manufactured by forcing a material through a custom pre-cut shape in die. Extruded aluminum is usually of a heavier gauge than formed metals and is heat treated for strength.
F
Fascia
Any formed or extruded metal product placed vertically on the face of a building. It is used to terminate single-ply, modified, built-up or residential roofing systems, and is located near the perimeter of the roof line. May be finished to fulfill specific decorative requirements (gravel stop, drip edge, 2 pc. gravel stop).
Flange
The length of formed sheet metal material which extends horizontally over the roof perimeter, for attachment of a sheet metal product and/or flashing-in roofing materials.
Flashing
Metal fabricated or formed to prevent water from entering a building at an object penetrating the roof (vent pipe) or a roof intersection (valley).
G
Gable Roof
A roof type constructed of two sloped sides of the same pitch.
Galvanized Steel, G-90
Steel coil/sheet which has been coated with a minimum 0.90 oz. of zinc per square foot giving the product excellent corrosion resistance. G-90 galvanized steel is considered an acceptable exterior grade material and is the dominant base material used for Kynar 500 finishes.
Galvanizing
The application of a zinc coating to steel either through hot-dipping or electrodeposition, giving the material added corrosion resistance.
Gauge
A material dimension expressed in terms of a system of arbitrary reference numbers. Dimensions expressed in decimals or metric dimensions are preferable.
Gravel Stop
A roof edge termination which derives its name from the function of holding back gravel or ballast (see fascia).
Gutter, Industrial Grade
A water carrying device at the roof edge used to collect rain water and melting snow from a roof surface. Manufactured in a material thickness starting at .032" and 24 ga. G-90 galvanized steel or greater.
H
Hip Roof
A roof type constructed of four sloped sides, coming to a point or a ridge.
I
Ice Dam
Snow or ice that melts at a warmer portion of a sloped roof and refreezes at the colder eaves, due to inadequate ventilation; additional water is prevented from draining from the roof and backs up under the roof system.
Intake Vent
An opening at a building's soffit that allows airflow in to ventilate the roof system.
J
Joint Cover
Formed metal pieces ranging from 3½" to 8" wide which are installed over the joints of abutting gravel stops, copings, gutter and counterflashings to prevent water entry and maintain joint integrity.
K
Kynar (50%)
A less expensive Kynar coating with 50% fluropolymer resin based formulation; colors are enhanced through ceramic pigmentation and are able to withstand extreme temperatures and atmospheric pollutants (Valspar - Acroflur).
Kynar 500 (70%)
An extremely durable 70% resin based paint coating, chemically known as polyvinylidene fluoride (PVDF). Fluorpolymers are factory applied baked-on finishes bonded either to coil or spray applied. then heated to 475 degrees Fahrenheit. Kynar 500 has unsurpassed exterior durability with warranties available up to 20 years (Akzo-Trinar, DuPont-Dublear, Glidden-Nublear, Morton-Fluorceram, P.P.G.-Duranar, Valspar-Fluropon.
L
Lap Joint
A seam located at the end of a sheet metal product created by placing 1"-3" over (or under) the end of an adjacent section, eliminating the need for cover or splice plates.
M
Metallic Finish
A premium paint finish that incorporates metal flakes to lend a sparkling, brilliant appearance.
Mill Finish
Aluminum provided in its raw, unfinished form; color and/or shade variations can be expected.
Miter, Inside or Outside
A fabricated accessory sometimes referred to as a corner, usually installed at the intersection of two walls;it is produced by cutting or bending two pieces of material and seaming them together.
N
Nailer
Any piece of construction grade wood attached to a building substrate which is used as a foundation for fastening steel or aluminum roof termination products. [also known as treated wood nailer]
Net Free Area (NFA)
The amount of total unobstructed area that will allow air to enter or exhaust a vent system.
O
Oil Canning
The perceived waviness of a section of flat metal which exceeds the limits for flatness in relationship to face height (or span) and metal thickness. Oil canning is an inherent part of light gauge formed metal products, particularly those products with broad flat areas. Structural integrity is not affected when oil canning is present.
Outlet
A short metal tube which is installed into an opening in the bottom of a gutter or downspout scupper. Used as a transition between the downspout sections and the water collecting system. [also known as drop tube or drop]
P
Paint Grip, Steel
G-90 galvanized sheet or coil which has been chemically treated with a phosphate film. This treated material does not require additional cleaning or weathering to provide a suitable paint substrate (bonderized, phosphatized).
Parapet
A perimeter wall which extends higher than the roof level.
Passive Ventilation
An unpowered ventilation system that draws air at the eave and exhausts at the ridge under the roof deck.
Pitch
The slope of a roof, expressed in inches of vertical rise over 12 inches of horizontal run.
Post-Coated
A paint or anodized finish process which is applied to a product after it has been formed into the final working shape.
Prefinished
Materials which are furnished with a factory applied paint (Kynar 500) or anodized finish prior to sheet metal fabrication. Prefinished usually refers to flat metal already painted in sheet or coil form.
Q
Quicklock Joints
A method of seaming two pieces of sheet metal together without penetrating materials. Provides a no-leak lock and 20 year warranty on prefinished sheet stock.
R
Radius
A dimension measuring from the center of a circle to the outer edge (½ the diameter). Sheet metal or extruded aluminum roofing products which are produced to conform to a circular or arched building condition.
Rake
The inclined overhang of a gable roof.
Reglet
A horizontal masonry saw cut or raked mortar joint used to receive sheet metal counterflashing, sometimes referred to as a receiver (see counterflashing, 1 pc. or 2 pc.).
Ridge
The horizontal line at the junction of the top edges of two sloping roof surfaces; the rafters of both slopes are nailed to a board at the ridge.
S
Scupper
An opening in the side of a wall or sheet metal edge detail which allows water to drain from the roof surface. Overflow scuppers are used as a secondary drainage method in case of interior drain blockage. Spillout scuppers allow water to run directly over the edge of a building onto another roof level or the ground. A downspout scupper (sometimes referred to as a collector or conductor head) channels water into a downspout which carries rain water to the ground or to a lower roof level.
Slope
The degree of roof incline expressed as the ratio of the rise (expressed in inches) to the run (expressed in feet).
Slotted Drain Bar
A heavy gauge perforated steel or aluminum bar, mounted at the perimeter edge of a building (usually above or in conjunction with a gutter system) allowing water to flow over the roof edge while retaining ballast, debris or pavers on the roof (Dutch gutter, flow through gravel stop, drain bar).
Soffit
The underside of the eave.
Soffit Cleat
An aluminum or steel product which closes off or covers the underside of a soffit or nailer, while continuously engaging a gravel stop, coping or extender at its lower edge (closure cleat, soffit closure).
Splice Plates
Formed metal pieces ranging from 3½" to 8" wide which are installed underneath the joints of abutting gravel stops, copings, gutters and counterflashings to prevent water entry and maintain joint integrity. Splice plates provide a more aesthetically pleasing appearance than cover plates (joint splice).
Sump
A variable sized opening at the building perimeter fashioned through a tapered edge or cant strip, level to the roof surface, which allows water to drain over the building edge.
T
Thermal Movement
The dimensional change of a building or metal caused by climatic temperature variances or the freeze-thaw cycle.
T-Miter
A steel or aluminum sheet metal product which is used at the junction of two parapet walls, where one wall terminates perpendicularly into a continuous second wall.
Transition Miter
A steel or aluminum sheet metal product which is utilized at the junction (corner) of two parapet walls of different wall thickness.
Treated Wood
Wood nailers which are pressure treated with salt preservatives for enhanced weather resistance, rot prevention, decay or insect damage.
Truss
A framework of beams (like ribs) that support the roof.
V
Vent
Any device installed in a roof, gable or soffit used to create ventilation underneath the the roof deck; any outlet for air that protrudes though the roof deck i.e. a pipe or stack.
Vinyl Masking
A strippable plastic film applied for protection during fabrication, shipping and installation of various sheet metal products. This film must be removed immediately before product installation. [also known as protective masking]
W
Wash Coat
A coating of 0.3-0.4 mil dry film thickness applied to the back or unexposed side of painted steel or aluminum sheet, to protect the adjacent top coat (Kynar 500) and help prevent corrosion on the reverse side.
Waterdam
The sheet metal component of a two piece fascia system which is installed over or under a roofing membrane (stripped-in if necessary) to terminate the material at the roof edge. It provides a foundation for a fascia cover to be snapped over the top without the aid of exposed fasteners. Once the fascia system is completed, the waterdam retains the flow of water over the roof edge.