What is a Downspout, Anyway? Your Straightforward Guide

When rain falls on your home's roof, it collects in the gutters before draining through an essential, yet often overlooked, component of your house's drainage system - the downspout. But what exactly is a downspout and what purpose does it serve? This straightforward guide will provide a deep dive into everything you need to know about downspouts as a homeowner.

Defining Downspouts: What Are They?

A downspout, also known as a rainspout, drainpipe, or conductor, is a vertical pipe that carries rainwater collected from your home's gutters downwards from the roof to the ground. The terms downspout and drainpipe are often used interchangeably.

Downspouts are typically made of galvanized steel, aluminum, copper, vinyl, or plastic. They come in various shapes and sizes to fit different types of gutter systems. The most common designs are round, square, and rectangular downspouts. Their main purpose is to serve as a pathway to divert rainwater away from your home's foundation and protect it from water damage.

Where Are Downspouts Located on a House?

Downspouts are attached below the gutters on the exterior walls of a home, usually positioned at the corners where two sections of gutter meet. Additional downspouts can be installed midway between corners if the length of gutter runs exceed 30-40 feet.

Their key placement is to redirect water away from the building's foundation. Having them located on all sides of the home ensures proper drainage no matter which direction wind and rain may come from.

What is the Function of a Downspout?

The main function of any downspout is to carry rainwater collected in the gutters down to the ground, away from your home's foundation and exterior walls. During heavy rains, gutters can quickly fill up with thousands of gallons of water. Without downspouts to divert it elsewhere, all this weight and pressure can lead to water leakage, flooding, concrete cracking, wood warping, and extensive structural damage.

By transporting gutter water vertically down the exterior of walls and deposits it at least 5-10 feet away from your home, downspouts play an integral role in an effective drainage system. This prevents saturated soil and water pooling around the foundation, keeping your basement or crawlspace dry.

Why Are Downspouts So Important for Homes?

Downspouts serve a critical purpose for homes. Here are some of the key reasons proper downspout installation and function are vital:

• Prevent water damage to walls, siding, windows, and doors
• Keep basements and crawlspaces dry and prevent potential flooding
• Avoid soil erosion around the foundation
• Stop water leaks leading to mold/mildew growth
• Reduce risk of foundation cracking, settling, or collapse
• Prevent ice dams and interior damage during winter
• Divert thousands of gallons of rainwater safely away from house

Without downspouts in place, all the rainwater landing on your roof has no dedicated path to drain away from the structure. This exponentially increases the risk of expensive structural repairs.

What Factors Determine How Many Downspouts You Need?

Several important factors come into play when determining how many downspouts your home requires:

• Gutter size - The general recommendation is one downspout for every 40 feet of gutter. Larger 6" gutters may need downspouts every 30 feet instead.
• Roof size and shape - Larger and more complex rooflines require more downspouts to handle greater rain runoff.
• Roof slope - Steeper angled roofs drain faster, requiring more downspouts than shallow-sloped roofs.
• Rainfall volume - Homes in wetter climates need more downspouts than those in drier regions.
• Surrounding landscape - Downspouts should be placed away from low, poorly draining areas to prevent pooling.

It's usually best to consult your contractor during installation for the ideal number, placement, and size based on your home's specifics.

Downspout Drainage Options

Once rainwater travels down the downspout, proper drainage planning is needed to move the water safely away from the foundation. There are a few main options for downspout drainage:

Splash Blocks

A splash block is a small pad made of concrete, plastic, or gravel placed on the ground under the downspout outlet. It prevents erosion by providing a surface for the water to hit before being diverted away from the house.

Downspout Extensions

Extensions are pieces of pipe, typically PVC or corrugated metal, connected to downspout outlets to redirect water several feet away from the building. They are an affordable way to prevent water pooling at the base.

Underground Drainage

In some cases, it may be necessary to connect downspouts to an underground drainage system. Flexible perforated PVC pipes are buried that channel water to underground catch basins or areas with better percolation.

Common Downspout Problems to Watch For

While durable, downspouts can develop issues over time that impede their drainage capacity if not addressed. Some problems to look out for include:

• Clogs - Leaves, grit, and other debris can accumulate in downspouts, causing clogs and water backups.
• Dislodgement - Downspouts can come detached from the wall due to age, weather, or improper initial installation.
• Leaks - Cracks and holes from impact damage, rust, or aging can lead to leaks.
• Improper drainage - If downspouts spill water too close to the home's foundation or into low areas.
• Rust/corrosion - Exposure to weather accelerates wear and rust buildup over time.

Downspout Maintenance Tips

To keep your downspouts working efficiently, here are some handy maintenance tips:

• Clear out any clogged debris from downspout openings using a plumber's snake.
• Re-secure any sections that have come detached from the wall using downspout straps.
• Check downspout joints and pipes for leaks, holes, dents, or corrosion.
• Ensure downspouts are angled or positioned to drain water at least 5 feet from the house.
• Extend downspouts further from the home with splash blocks or downspout extensions if needed.
• Inspect for proper alignment and damage during heavy rains to observe water flow.

Inspecting and clearing out downspouts should occur a few times per year, especially after heavy storms with lots of wind and leaf debris.

How to Replace a Damaged Downspout

If your downspout is beyond repair from rust, leaks, or physical damage, replacement is necessary. Here are the steps for this project:

1. Carefully remove the damaged downspout sections from the wall gutter hangers or straps.
2. Measure and purchase replacement downspout pieces of the needed size and material. Include elbows/bends if necessary.
3. Snap new downspout sections into the existing wall hangers beginning at the top. Use sheet metal screws to reinforce connections.
4. Connect an elbow piece to the bottom downspout outlet to redirect water away from the home.
5. Attach a splash block or extension if needed to complete the new drainage path.
6. Seal any gaps with caulk and test water flow during the next rain.

For new home builds, downspouts can be incorporated right from the start. Here's an overview of new downspout installation:

• After gutters are installed along the roofline, determine the ideal number and locations for downspouts based on gutter length/configuration and roof design.
• Select downspout material and shape to match gutters. Measure from the roof to ground at each downspout spot.
• Cut downspout pipes to needed lengths. Preassemble elbows and pieces on the ground for easier lifting.
• Secure wall straps and hangers going down the wall where pipes will be located.
• Fit the downspout assembly into the hangers against the wall, securing with screws at each joint. Attach gutter outlets to top of downspouts.
• At the ground, install splash blocks or downspout extensions to direct water away from the foundation.

For optimal performance, integrate downspouts into the construction plans from the beginning. This allows proper placement coordinated with the gutter and drainage systems.

Whether you are installing new downspouts or maintaining existing ones, remember that routinely inspecting and cleaning these rainwater conductors is essential preventive maintenance. Catching minor issues early on can avoid extensive repairs down the road. Your downspouts play an integral yet underappreciated role in protecting your home from the elements.