Glossary of Gutter Terms and Definitions

Most homeowners know what gutters and downspouts are, but when it comes to other gutter-related terms, they may be at a loss. This handy glossary from Pacific Gutter will provide you with all you need to know about gutter terms and their definitions.


Aluminum: A light silver-colored metal that is number 13 on the periodic table of elements. It has a lower density than other common types of metals, and it’s the most widespread metal on the planet. It’s also the most common material for gutters to be manufactured from. Aluminum gutters are available in a wide variety of colors to match exterior trim.


Box Miter: Two short lengths of gutter mechanically formed into a single piece with a right angle, used to connect gutter sections at a corner.


Cap Flashing: The part of flashing that is connected to a vertical surface to block moisture from seeping behind the base of the flashing.

Chimney Cap: A cover for the top of a chimney or vent that allows smoke or steam to escape, but protects the opening and the masonry of the chimney from rain, falling leaves or pine needles and other debris.

Copper: A soft, malleable metal that is number 29 on the periodic table of elements. Copper gutter systems have the highest upfront cost for installation, but they typically last longer than other types. Since copper oxidizes and develops a patina, copper systems will eventually turn a muted green color.


Downspout: Also referred to as a leader or leader pipe, the downspout is a vertical pipe that drains rainwater out of the gutter, down the side of a building and into a downspout extension or drain where it can be disposed of away from the building. Downspouts are available in various shapes and sizes to accommodate your gutter system and rainwater volume.

Downspout Screen Insert: A rounded mesh or wire strainer that fits inside an outlet tube to block debris from getting into downspouts that empty into underground drains. This is necessary because unblocking an underground drain is far more difficult than clearing out a clogged gutter or downspout.

Downspout Extension: These pipes connect to the bottom of a leader pipe and run horizontally across the ground (with a slight pitch to keep the water moving). The purpose is to force rainwater further away from the house so it doesn’t pool near the foundation.

Dry Well: An underground container where rainwater from an underground drain is deposited to avoid issues such as soil erosion. They are often simply small concrete cesspools buried in the ground.


Eaves: The edges of a roof that overhang the exterior wall and typically extend beyond the side of a building to shelter the outside. Eaves direct rainwater away from the exterior of a building and are the point at which gutters are attached. In some building styles, they are decorated with elaborate design elements.

Elbow: The curved connection piece that connects gutters to downspouts and is used at the bottom of downspouts to connect an extension piece. There are various shapes and sizes of elbows, including round, square and offset.

Electrolytic Corrosion: Accelerated metal corrosion during which a metal surface that is in contact with another metal, an electrolyte and an electrical current deteriorates rapidly.

End Cap: These caps are placed on the end of a gutter trough to give the system a more finished look and to prevent water from spilling backwards out the wrong side of the trough.


Fascia: The part of the roof eaves that caps off the edge of an eave, running parallel to the exterior wall at the lowest point of the roofline. Fascia boards are typically where gutters are attached, and they’re commonly made of materials such as wood, aluminum, vinyl and cement fiberboard.

Ferrule: Small cylindrical tubes that spikes are inserted into when the gutter is installed. Ferrules go through the lip of the gutter and span its width, allowing the spike to enter the fascia board and secure the gutter.

Flashing: An L-shaped strip of metal that closes up gaps between gutters and fascia boards and can also be used to waterproof other vulnerable areas such as around a chimney.


Galvanized Steel:  This common gutter material is made with steel that has been galvanized with a protective zinc coating that makes it resistant to rust. Galvanized steel gutters are stronger than aluminum or copper, but they are also heavier and can cause additional wear and tear to hangers and fascia boards.

Gauge: The thickness of the aluminum used to manufacture gutters and Gutter Shutter guards. The necessary gauge depends on the climate. In a temperate climate with frequent rainfall and snowfall, and strong wind, a thick gauge of 0.032 is recommended.

Gutter: A trough that attaches to the edge of your roof eave on the fascia board and collects all the rainwater that falls on your roof, channeling it into downspouts. Gutters are essential rainwater disposal systems that protect buildings from severe water damage, ranging from a leaking roof to a cracked foundation.

Gutter Cover:  A type of gutter guard that fits underneath roof shingles. Because of this, gutter cover installation often voids roof warranties. They are also highly visible and can compromise curb appeal.

Gutter Filter: Mesh that covers the top of gutters to prevent leaves and other debris from getting in. They clog frequently and need to be maintained with brush cleaning to avoid algae growth.

Gutter Guard:  Any type of device designed to block leaves, trash and other debris from getting into gutters, including covers, filters, screens and Gutter Shutter gutter guards.

Gutter Screens: Metal or plastic pieces that are perforated with holes or slats and go over the top of gutters to prevent debris from getting in. However, they also limit the flow of water and need to be manually cleaned to avoid insect infestations and organic growth.

Gutter Shutter: An all-in-one gutter guard solution that eliminates many of the problems with other types of gutter guards. Using the principles of surface tension, rainwater streams across the Gutter Shutter and into an opening while leaves and other debris simply fall off the edge without approaching the opening. They will never clog or fill with debris, drastically reducing the time you need to spend maintaining your rainwater disposal system. Gutter Shutter attaches directly to your fascia board without affecting your roof shingles, and it’s visually low-profile so it doesn’t impact curb appeal.


Hanger: The pieces that are used to attach the gutter to the fascia board. There are different types of hangers, including spikes and ferrules, straps and brackets, and hidden hangers.

Hidden Hanger: A bracket and screw that attaches gutters to fascia boards. It sits inside the gutter, over top of the channel rainwater flows down, so it’s not visible from the outside unless you’re looking straight down into the gutter.


Leader Pipe: Also referred to as a downspout, a leader or leader pipe is the vertical pipe that connects to a gutter and channels rainwater down the side of a building into a downspout extension or underground drain.


Miter: A corner piece that connects two straight lengths of gutter so the channel can go around a corner of a roof. There are two main varieties available—box miters and strip miters.


Offset Elbow: Also called a “bump out” elbow, these connectors go between gutters and downspouts, and can be bent in two places to fit neatly around ledges, decorative elements and anything else that is in the way of the vertical leader pipe.

Outlet Tube: Alternatively called a pop-in, this short, round tube is placed inside the gutter hole and the leader pipe then fits over top of it. It is not visible from the outside but helps to avoid leaks at the critical juncture between the gutter and downspout.


Pipe Cleat: Used to attach downspouts to a house, these metal brackets or clips wrap around the downspout and screw into the building’s siding on both sides.

Pitch: The necessary angle that a length of gutter must be positioned at to keep rainwater moving downward toward the leader pipe. Without adequate pitch, the water will just sit in the troughs without moving.


Rainwater Volume: A measure of the amount of rainwater that falls on your roof and moves through your gutter system. Rainfall is usually measured in inches, but the output can be converted to gallons. For example, one inch of rain on a 1,000 square foot roof results in about 620 gallons of water.

Rake Board: This roofline trim is very similar to fascia boards and is generally made from the same material. The only difference is that the rake boards are slanted and rise upward to the peak of the roof instead of remaining parallel to the ground and exterior wall like fascia does.

Round Elbow: Connectors used to hook up round, non-corrugated downspouts with gutter troughs.

Run Height: The height of the gutter system in stories (first story, second story, etc.) which is needed to calculate how long the downspouts will be to reach the ground.

Run Length: The length of a straight stretch of gutter attached to the fascia board, measured in linear feet.


Scupper Box: Alternatively referred to as a leader box or conductor head, these parts are used to collect rainwater from a flat roof or a commercial building that doesn’t have a gutter system and funnel it into downspouts. They are sometimes also used as decorative exterior trim components.

Silicone: A flexible polymeric elastic substance that is used to seal up gaps, cracks, joints, holes and other parts of the system to make it more watertight.

Slip Joint: This small part, which is usually C-shaped, covers the joint between two straight sections of gutter where they meet.

Soffit: Soffit boards cover the underside of roof eaves. They are ventilated with holes or slats that increase air circulation in the attic space to help rid it of excess heat and humidity to avoid moisture damage inside the attic.

Spike: These are essentially gutter nails that hold the troughs onto the fascia boards, usually in combination with ferrules. They come in various materials and styles, including smooth, ridged, aluminum, galvanized steel and copper.

Splash Block: A long tray with a gentle slope and one open end. It is placed underneath a downspout to prevent water from pooling underneath the exit point, eroding soil or damaging the surface directly below the leader pipe.

Square Elbow: Like any other type of elbow, these connect gutter troughs to downspouts. They are actually more rectangular than square and can be oriented in either direction according to how the downspout is installed.

Strainer: Also referred to as a downspout screen insert, these rounded mesh pieces are inserted into the top of a downspout that connects to an underground drain to prevent leaves and other debris from entering the difficult-to-clean drain.

Strap: Strips of metal that are bent around the downspout and used to attach it vertically to a wall. They are also sometimes called leader bands.

Strap Hanger: A type of hidden hanger that sits inside the gutter trough and attaches it to the roofline with a metal strap that is nailed or screwed to the roof either over top of or underneath the roof shingles. The strap part is usually visible.


Trough: The part of a gutter system that is attached to the eaves. This long, narrow channel carries rainwater from the roof to a downspout.


Underground Drain: A buried pipe that attaches to the bottom of a leader pipe and deposits rainwater into a dry well. They are prone to clogging and it’s difficult to clean them out without digging them up.


Vinyl: A plastic polymer made from polyvinyl chloride, this durable, inexpensive material is a common choice for gutters. Vinyl does not corrode, rust or rot, but it is prone to warping and cracking.


Wedge: A triangular bracket that clips on to the back of a gutter and holds it at the right angle when attached to angled fascia boards that don’t run perpendicular to the ground.


Y-Connector: A Y-shaped connection piece that allows two leader pipes to be combined into one. The two pipes attach to separate openings at the top and a single downspout at the bottom.