References & Glossary

Apron flashing:
A horizontal flashing installed where the top end of a roof slope meets a vertical projection, such as a chimney or parapet wall.

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Barge:
A finishing at the gable end of a roof, fixed parallel to the roof slope.
BMT:
Base metal thickness
Box Gutter:
A gutter not at an eave, typically at the base of two opposing roof slopes.

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Capping:
A cover at the top of a gap that weatherproofs, typically at the ridge of a pitched roof.
Cladding:
Sheeting that encloses a building-roofing and walling.
Colours:
Ask color samples from 'URS'.
Concealed-fastened:
A method of fixing Roof & Cladding by means of hidden, fixing clips or brackets (sometimes called secret fixing).

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Downpipe:
A pipe to carry roof water from gutters and roof catchments to drains or storage tanks.

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Eaves Gutter:
A roof gutter attached at an eaves overhang.
Elbow:
A fitting used in a downpipe, to change direction of the downpipe by about 90 degrees.
Electrolytic (galvanic) Corrosion:
Corrosion resulting from the contact of two different metals when an electrolyte (like water) is present.
Expansion Joint:
A joint in a long run of cladding, gutter or flashing designed to allow for thermal expansion and contraction.

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Fall (slope):
The slope of the roof or gutter, often expressed in degrees, or as a ratio of vertical height to horizontal distance (e.g. 1 in 20).
Fascia (fascia board):
A board, or rolled metal product of similar dimensions, fixed along the eaves, to which a gutter is secured.
Flashing:
A material, usually metal, used to waterproof the junction between two intersecting roof and/or wall surfaces. At a masonry wall, it is often built into the mortar.
Apron Flashing - A flashing used to obtain a weathertight joint, usually where a roof abuts a vertical wall.
Counter (or over) Flashing - A flashing dressed down as a cover only, over a separate upstand.
Hanging Flashing - Side front or back cover piece used to prevent entry of water between abutting surfaces and other gutters, flashings and soakers.
Soaker Flashing - A side cover piece extended over a roof cover and overflashed with a hanging flashing.

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Galvanized Steel:
Steel sheeting protected against corrosion by a zinc coating applied by the continuous hot-dip process.
Galvalume Steel:
Steel sheeting protected against corrosion by a zinc & Aluminum coating applied by the continuous hot-dip process.
Girth:
The width of the blank strip from which a profile is rolled (usually refers to gutters and flashings).
Gutter:
A channel that collects roof water and carries it to an outlet.

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Mansard:
A roof built at two pitches, the steeper pitch commencing at the eaves and the flatter pitch finishing at the ridge.

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Offset:
A pipe fitting that directs a downpipe from the gutter, under the eaves soffit and down a wall.
Oilcanning:
Variation from flatness of sheet metal, creating undulations along the surface. The result is poor appearance and potential ponding.

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Pan:
The flat portion between the ribs in a pan-type preformed sheet.
Parapet:
A wall on the perimeter of a building that projects above the line of the eaves.

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Penetration:
A projection through the roof, e.g. vent pipe, chimney or rooflight.
Pierce-fastened:
A method of fixing cladding by means of a screw or nail which pierces the cladding.
Ponding:
Pooling of undrained water on a roof.
Pop:
A short fitting in a gutter sole, where rainwater leaves the gutter.

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Rainhead:
A box-shaped receptacle sometimes used between gutters and downpipes to provide an external overflow point.
R-value:
A value given for the resistance to heat transfer of a roof or wall system.
Rib:
A longitudinal upstand in cladding.
Ridge Capping:
Formed metal designed to weatherproof the junction at the apex of opposing roof slopes.

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Sarking:
A membrane to collect and discharge clear of the structure any water that may penetrate a roof or wall cladding.
Shoe:
A fitting used in a downpipe, to change direction of the downpipe by about 45 degrees.
Soaker (gutter):
A small gutter located on the upper side of a chimneystack.
Soaker (flashings):
Formed metal designed to weatherproof the perimeter of roof protrusions or penetrations. Soaker flashings are usually positioned under rather than over the surrounding metal roof.
Sole:
The internal, bottom surface of a roof gutter.
Spreader:
A downpipe-tee or elbow fixed at 90 degrees to the roof slope used to spread stormwater over a greater area of the roof.
Spouting:
See Gutter.
Straps:
A metal band used to secure a downpipe to a wall.
Sump:
A roof gutter pit used to connect downpipes to internal roof gutters.

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TCT:
Total Coating thickness
Thermal Stress:
Stress due to expansion and contraction caused by changes in temperature.

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Valley Gutter:
A gutter at the bottom intersection of two sloping roofs (also called a valley flashing).
Valley Boards:
Timber or profiled metal laid under a valley gutter to support it.

Zincalume:
Steel sheeting protected against corrosion by an aluminium-zinc coating