Definition of a Rain Gutter:

A rain gutter (also known as eaves trough, guttering or simply as a gutter) is a narrow channel, or trough, forming the component of a roof system which collects and diverts rainwater shed by the roof. In many buildings, the purpose of this diversion is to prevent water from falling off the roof edges. This uncontrolled water can cause structural damage to the outside walls and/or the foundation of a building over time. Another purpose of rain gutter is to harvest rainwater for household or garden use.

Rain gutters can be constructed from a variety of materials, including galvanized steel, painted steel, copper, painted aluminum (also known as Seamless Aluminum), PVC (and other plastics), concrete, stone and wood.

Water collected by a rain gutter is fed, usually via a downspout, into a collection system. A collection system can be a rainwater tank, a storm water main, or a sewer main (depending upon local codes). In some locations where collection to a main is not feasible, the water is dispersed into a storm water pit or cistern.

Different styles of gutter are available to suit the design of the roof and house. Exterior rain gutters are available in a variety of profiles to suit the appearance of the building. Exterior rain gutter is fixed to the fascia board, which in turn is fixed to the ends of the rafters. A fascia gutter incorporates a rain gutter with a fascia. A box gutter is a deep gutter, which is concealed within the structure of the roof. A box gutter is usually applied when the rainwater is to be collected from points within the boundary walls of the building. Water collected by a box gutter is fed to the down-pipe via a rain head.

One of the most popular forms of rain gutter is "Seamless". This is a method by which long lengths of gutter can be made on site and therefore avoiding seaming of sectional gutters. Seamless gutters are available in a variety of metals, shapes, sizes, and finishes.

Rain gutters can be equipped with gutter screens, louvers or solid hoods to allow water from the roof to flow through, but block leaves and other debris from entering and building up in the gutter.

Rain gutters can have their drains directed to rain collection systems that allows the saving of the rain water for use later, or into an underground pipe system the leads to the street or other collection areas.

A possible origin of the word "gutter" can be traced to the Latin word gutta, which means drop or droplet.

Below is a comprehensive list of common industry terms associated with Rain Gutters and Rain Gutter Protection.

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.

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.

Bid: 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 and conditions stated in the offer.

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.

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

Chimney Gutter: See Soaker.

CGI: See Corrugated Roofing.

Cladding: Sheeting that encloses a building-roofing and walling.

Counter (or over) Flashing: A flashing dressed down as a cover only, over a separate upstand.

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

Drainage: A system of gutters and drainpipes that carry water away from the foundation of a house.

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

Drop: 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.

Elbow: 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 and 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 give the roof edge a more finished look and provide a base for attaching gutters.

Fixings Screws: nails or clouts used to fasten cladding to a building structure.

Flashing: 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.

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

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

Hanger: 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 and other gutters, flashings and soakers.

Inside miter box: A corner piece of the horizontal section that is deflected in.

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

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

Nozzle: See Pop.

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.

Outside mitre box: A corner piece of the horizontal section that is deflected out.

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.

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.

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

Ponding: Pooling of undrained water on a roof.

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

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.

Run: Length of a horizontal section of gutter.

Saddle Strap: See Straps.

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): A side cover piece extended over a roof cover and overflashed 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.

Sole: The internal, bottom surface of a roof gutter.

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

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.

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

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

Thermal Stress: Stress due to expansion and contraction caused by changes in temperature.

Trays: 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.

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