A Rain Barrel Needs a Route for Water When It Is Full

You want to collect roof water for the garden, and the downspout beside the patio looks like the obvious place for a rain barrel. Before anyone cuts that downspout, settle one detail: where will the water go when the barrel is full? The answer should be a visible, deliberate route. A barrel that collects water successfully but spills the rest beside your basement wall has only solved half the problem.

For a St. Louis homeowner buying gutter guards at the same time, this is worth discussing before installation. The guard, downspout, diverter and barrel do different jobs. Keeping leaves out of the gutter does not decide where excess water goes, and a barrel does not replace the drainage route your house already needs.

Gutters and guards

Start with the full barrel

Picture the barrel already full when the next rain begins. That is a useful way to judge the proposed connection because storage is no longer helping. Every additional gallon reaching that downspout needs somewhere else to go. You should be able to trace that path from the connection to the existing discharge point without relying on someone remembering to open a tap.

Some diverters are designed to send water into the barrel while it has room, then let water continue through the downspout. Other arrangements feed the barrel from above and depend on a separate overflow connection. Those are different setups. Ask the installer to identify which one is proposed and explain how it behaves when the barrel fills. The word "diverter" on a quote is not enough to answer that question.

If the downspout currently carries water through an extension toward a suitable discharge area, the barrel installation should account for that route. Do not assume a short overflow hose dropped behind the barrel does the same job. Look at where it ends, whether it can stay in place, and whether the surrounding ground directs water back toward the house.

A gutter guard is not a barrel filter

A guard can keep larger debris out of the gutter while smaller material still reaches the downspout. Water entering a barrel can carry fine sediment and roof debris. The barrel's inlet screen, lid and cleaning access still matter, even when guards cover the entire gutter run above it.

Ask to see how the inlet screen comes out after the barrel is connected. If servicing it requires shifting a full barrel or pulling apart a rigid pipe, a small cleaning task becomes difficult. Leave enough access to inspect the inlet, remove collected material and reach the barrel's drain. The connection should fit the maintenance instructions for the equipment you are buying.

Collected roof runoff is not drinking water. A gutter guard does not change that. If your intended use requires particular water quality, resolve that separately rather than treating clear-looking water as evidence that the guard has cleaned it.

How much storage are you actually adding?

A barrel can fill sooner than its size suggests. One inch of rain on 100 square feet represents about 62 gallons of water before collection losses. That is a volume calculation, not a promise that every gallon will reach your barrel. It does explain why a single garden barrel needs an overflow plan even beneath a relatively small roof area.

The relevant roof area is the portion draining toward that downspout. It is not necessarily the roof directly above the barrel. A gutter may bring water from farther along the eave, and an adjoining roof slope may contribute to the same run. Ask which roof sections feed the connection before deciding that one barrel will hold a particular storm's runoff.

Your watering habits also affect the available space. If you use little water between rains, the barrel may still be nearly full when another storm arrives. Adding a second barrel increases storage, but eventually that storage can fill too. Size the collection setup around your intended use while keeping a working route for water beyond its capacity.

Leave room for the winter arrangement

St. Louis weather can move between freezing and thawing during winter. Follow the barrel and diverter manufacturers' winter instructions, including any directions to drain, disconnect or store components. Do not assume that leaving the barrel's tap open satisfies every part of those instructions. Hoses and fittings need attention too.

Before installation, ask what reconnects the downspout when the barrel is taken out of service. You may need a removable section, a cap or a seasonal setting on the diverter, depending on the product. Have the installer show you the actual arrangement. A disconnected barrel should not leave an open downspout pouring water onto the ground beside the wall.

Keep any seasonal parts together somewhere you can find them. Labeling a short replacement downspout section with its location is useful if you have several barrels. You should not have to reconstruct the installation from memory on the first cold evening of the season.

What it costs

The barrel's purchase price is only one part of the work. A complete estimate may include a diverter, connecting hose, downspout alterations, an overflow route and preparation of the supporting surface. If you are also buying gutter guards, ask for the barrel connection to appear as a separate item so you can see what it adds.

The support deserves a specific description. Water alone in a full 50-gallon barrel weighs about 417 pounds, before adding the barrel's own weight. A stand or base needs to suit that load and the manufacturer's requirements. Raising the barrel to fit a watering can under the tap changes the support arrangement; it should not be an improvised stack assembled after delivery.

Access can change the work as well. A narrow space between a fence and the house may fit the barrel but leave little room to connect or service it. A location farther from the downspout may need a different connection. Have those details settled before comparing prices, rather than comparing a barrel-only price with a complete installation.

Ask what the quoted price assumes about the existing downspout discharge. Connecting a barrel is one task. Repairing a damaged extension or investigating an existing underground drain is another. The estimate should say whether either is included if those conditions are present.

What to ask

Walk to the proposed location with the person preparing the estimate. These questions are easier to answer while looking at the downspout, the ground and the space available:

• When the barrel is full, exactly where does the next gallon go?
• Does the proposed diverter fit this downspout and this barrel?
• Can I remove the inlet screen and reach the drain without moving the barrel?
• What supports the full barrel, and who prepares that surface?
• What parts do I need to return the downspout to its winter arrangement?
• What will you check before calling the connection finished?

A controlled water check can help reveal leaks at connections and show whether water follows the intended route. It does not reproduce every storm. Ask for a demonstration of the overflow or bypass function as well as the filling function, following the product instructions. Watching an empty barrel accept water does not establish what happens when it is full.

To discuss the gutter and downspout portion with Keys Roofing, the contractor behind Gutter Guards STL, call (314) 220-2333. Have the barrel model or installation instructions available, along with a photo showing the downspout all the way to its current discharge point.