Industry Terms

Industry Terms

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.


A finishing at the gable end of a roof, fixed parallel to the roof slope.


Base metal thickness.

Box Gutter

A gutter not at an eave, typically at the base of two opposing roof slopes.


A formal offer by a contractor, in accordance with specifications for a project, to do all or a phase of the work at a certain price in accordance with the terms & conditions stated in the offer.

Box Miter

Adjoins to pieces of gutter at a 90 degree angle inside or outside.

Brick mold

Trim used around an exterior doorjamb that siding butts to.

Built-up roof

A roofing composed of three to five layers of asphalt felt laminated with coal tar, pitch, or asphalt. The top is finished with crushed slag or gravel. Generally used on flat or low-pitched roofs.

Cap flashing

The portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.


A cover at the top of a gap that weatherproofs, typically at the ridge of a pitched roof.

Chimney Gutter

See Soaker.


See Corrugated Roofing.


Sheeting that encloses a building-roofing & walling.

Counter (or over) Flashing

A flashing dressed down as a cover only, over a separate upstand.


A pipe to carry roof water from gutters & roof catchments to drains or storage tanks.


A system of gutters & drainpipes that carry water away from the foundation of a house.

Drip Edge

A non-corrosive, non-staining material used along the eaves & rakes to allow water run-off to drip clear of underlying construction.


See Pop.

Drop Outlet

Formed piece that serves as the hole from which the water travels from the horizontal section of the gutter to the downspout.

Eaves Gutter

A roof gutter attached at an eaves overhang.


Pre-finished angled piece for directing water flow.

Electrolytic (galvanic) Corrosion

Corrosion resulting from the contact of two different metals when an electrolyte (like water) is present.

End Cap

Flat formed piece that is placed at the end of a gutter section.

Expansion Joint

A joint in a long run of cladding, gutter or flashing designed to allow for thermal expansion & contraction.

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 flat board that runs horizontally along the eaves of a roof, typically capping the ends of the roof rafters to donate the roof edge a more finished look & provide a base for attaching gutters.

Fixings Screws

nails or clouts used to fasten cladding to a building structure.


A material, usually metal, used to waterproof the junction between two intersecting roofs and/or wall surfaces. At a masonry wall, it is often built into the mortar.

Galvanized Steel

Steel sheeting protected against corrosion by a zinc coating applied by the continuous hot-dip process.


The width of the blank strip from which a profile is rolled (usually refers to gutters & flashings).


Horizontal channels installed at the edge of a roof to carry rainwater or melted snow away from the house.


Flat strap that is installed under the roofing material that holds up the horizontal section of the gutter.

Hanging Flashing

Side, front, or back cover piece used to prevent entry of water between abutting surfaces & other gutters, flashings & soakers.

Inside miter box

A corner piece of the horizontal section that is deflected in.


A pipe that carries rainwater from the gutters to the ground, sewers, or wells.


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

Mitered Corner

Where to pieces of gutter come together adjoined by either a box miter or a strip miter.


See Pop.


A pipe fitting that directs a downpipe from the gutter, under the eaves soffit & down a wall.


Variation from flatness of sheet metal, creating undulations along the surface. The result is poor appearance & potential ponding.

Outside mitre box

A corner piece of the horizontal section that is deflected out.


Built-in gutters are moreover referred to as “box gutters” or “pan gutters.” These gutters are considered concealed roof drainage systems because they are not easily visible.


A wall on the perimeter of a building that projects above the line of the eaves.


A projection through the roof, e.g. vent pipe, chimney or roof light.


A method of fixing cladding by means of a screw or nail which pierces the cladding.


The angle at which a horizontal section of gutter is tilted in order to force water to flow toward a downspout.


Pooling of un-drained water on a roof.


A short fitting in a gutter sole, where rainwater leaves the gutter.


A box-shaped receptacle sometimes used between gutters & downpipes to provide an external overflow point.


A value given for the resistance to heat transfer of a roof or wall system.


A longitudinal upstand in cladding.

Ridge Capping

Formed metal designed to weatherproof the junction at the apex of opposing roof slopes.


Length of a horizontal section of gutter.

Saddle Strap

See Straps.


A membrane to collect & discharge clear of the structure any water that may penetrate a roof or wall cladding.


A fitting used in a downpipe, to alter direction of the downpipe by approximately 45 degrees.

Soaker (gutter)

A small gutter located on the upper side of a chimneystack.

Soaker (flashings)

A side cover piece extended over a roof cover & over-flashed with a hanging flashing. 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.


The internal, bottom surface of a roof gutter.


Plastic or concrete surface put under a downspout to direct water away from the house.


A downpipe-tee or elbow fixed at 90 degrees to the roof slope used to spread storm-water over a greater area of the roof.


See Gutter.


Flat hangers that are nailed into the house to hold the downspouts in place.

Strip Miter

Adjoins to pieces of gutter at an angle 90 degree or 135 degree inside or outside


A roof gutter pit used to connect downpipes to internal roof gutters.

Tabbed Miter

Used to adjoin two pieces of gutter at a compound angle or non standard (ie 135 or 90 degree)

Thermal Stress

Stress due to expansion & contraction caused by changes in temperature.


See Pan.

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.


Steel sheeting protected against corrosion by an aluminum-zinc coating.