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What is a Rainwater Gutter?

Paul Woods
Paul Woods

A rainwater gutter is a U-shaped or K-shaped trough that is hung from the eaves of a building to catch water cascading off the roof before channeling it away from the structure’s foundation. The typical rainwater gutter system is comprised of three basic elements: the rainwater gutter trough; hangers, which are strips of metal affixed to the roof from which the guttering hangs; and a downspout, which is a vertical pipe through which water flows down from the rainwater gutter, alongside the structure, and away from the foundation. A drawback to an open gutter system is that it can become clogged thereby requiring a screen or covering that is added to the top of the gutter to keep out debris.

Rainwater gutters can be constructed from a variety of materials, including vinyl, wood, galvanized steel, and aluminum. Many homeowners prefer more durable materials, such as galvanized metal, because the constant exposure to sun and rain works to corrode the material. The size of a rainwater gutter varies with the amount of roofing surface that is being drained. Gutters typically are available in 4-inch (10.16 cm), 5-inch (12.7 cm), and 6-inch (16.24 cm) diameters. For about 600 square feet (55.7 square meters) of roof area, the 4-inch (10.16 cm) diameter is recommended. Similarly, downspouts come in a variety of diameters, with wider diameters recommended for higher volumes of water flow.

Coated in a protective layer of zinc, galvanized gutters are quite strong and usually can withstand any pounding that nature can bring, but may rust over time.
Coated in a protective layer of zinc, galvanized gutters are quite strong and usually can withstand any pounding that nature can bring, but may rust over time.

The problem a rainwater gutter is designed to solve centers on the negative impact of water collecting around a structure’s foundation. Pooled water erodes the dirt packed next to the foundation, and the resulting soil shift can lead to foundation shifting or cracks. The pooled water affects both slab and pier-and-beam foundations, and affects both residential and commercial property.

Rain gutters must be cleaned out regularly.
Rain gutters must be cleaned out regularly.

In addition to the basic components of a rainwater gutter system, there also are downspout elbows — short, angled pieces of pipe that join the drop outlet of the gutter to the portion of the downspout affixed to the house. At the base of the downspout, near the foundation, there typically is a splash block. This is a concrete piece shaped much like a dust pan with no handle. The falling water hits the splash block and is channeled away from the foundation. In certain instances, a splash block does not move the water far enough away therefore an almost horizontal pipe is affixed to the base of the downspout to channel the water into the yard.

Open gutters can be clogged by snow.
Open gutters can be clogged by snow.

Rainwater guttering systems decline in usefulness if they are clogged with leaves, twigs, or other debris that cascade off the roof. Systems typically can be purchased with a leaf screen to shield the gutter trough. Even with the leaf screen or other covering, a rainwater guttering system must be periodically cleaned out to prevent water from building up in the trough and falling over the edge to the foundation below.

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    • Coated in a protective layer of zinc, galvanized gutters are quite strong and usually can withstand any pounding that nature can bring, but may rust over time.
      By: alephcomo1
      Coated in a protective layer of zinc, galvanized gutters are quite strong and usually can withstand any pounding that nature can bring, but may rust over time.
    • Rain gutters must be cleaned out regularly.
      By: soupstock
      Rain gutters must be cleaned out regularly.
    • Open gutters can be clogged by snow.
      By: Omika
      Open gutters can be clogged by snow.