Ready to capture roof runoff and put it to work in your garden? This comprehensive how-to guide walks you through downspout diverter installation and shows you exactly how to link two rain barrels with reliable overflow protection. Whether you’re working with a 2×3 downspout or a 3×4 downspout, we’ll cover planning, tools, step-by-step setup, leak-free fittings, first flush strategies, and how to winterize your rain barrel system for years of trouble-free use.
Why Install a Diverter and Link Two Rain Barrels?
Installing a downspout diverter keeps your gutter system intact, safely directs water into barrels, and sends the excess back down the downspout when barrels are full. Linking two rain barrels increases storage, reduces overflow incidents, and provides steadier water pressure for gravity-fed hoses. Add a purpose-built overflow kit and you’ll protect your foundation, mulch, and siding from splash-back while maximizing your harvest during heavy storms.
Downspout Diverter Installation: Quick Overview
At a high level, downspout diverter installation involves cutting a precise opening in the downspout and inserting a diverter that channels water to your barrel via hose. When the barrel fills, the diverter’s internal mechanism (or the water’s natural rise) returns flow to the downspout. You’ll mount the barrel on a solid base, attach leak-free fittings, and test for drips. Then you can link a second barrel at the same height, add a secure overflow route, and optionally incorporate a first flush device for cleaner water.
Recommended Kits and Barrels
The products below are popular, widely available, and compatible with most residential setups. Use manufacturer instructions alongside this guide for exact steps and safety notes.
Top Diverter Kits
| Product | Type | Downspout Compatibility | Install Method | Includes | Best For |
|---|---|---|---|---|---|
| EarthMinded FlexiFit Universal Downspout Diverter | In-spout diverter with flexible port | 2×3 and 3×4 downspouts (with included template) | Cut port and insert flexible diverter; attach hose | Diverter body, hole template, hose, fittings | Versatility, neat appearance, simple maintenance |
| Oatey Mystic Rainwater Collection System | Cut-in collection head with hose outlet | 2×3 and 3×4 downspouts (adapter often required for 3×4) | Cut out section; insert Mystic head; connect hose | Collection head, hose, clamp, screws | Budget-friendly, straightforward retrofits |
Overflow Kit
| Product | Function | Key Features | Ideal Use |
|---|---|---|---|
| AquaBarrel Overflow Kit | Directs full-barrel overflow away from foundation | Large-diameter hose, bulkhead fitting, screen options | Heavy rainfall regions; dual-barrel setups |
Barrels to Pair With
| Barrel | Capacity | Ports/Features | Material | Notes |
|---|---|---|---|---|
| Good Ideas Rain Wizard 50 | 50 gallons | Brass spigot, overflow port, screen lid | Rotomolded polyethylene | Classic barrel look; sturdy; easy to link |
| Ivy 50 Gallon Rain Barrel | 50 gallons | Brass overflow, screen top, linking ports | Recycled, BPA-free polyethylene | Flat back for walls; municipal program favorite |
Planning Your Downspout Diverter Installation
A thoughtful plan ensures a clean install, maximum capture, and fewer leaks. Start by choosing a downspout close to irrigated areas. Confirm where overflow will safely discharge, such as into a yard, drain, or a permeable bed. Pick a level, shaded spot for your barrels – shade reduces algae growth and UV stress.
Measure Roof Area and Estimate Capture
As a rule of thumb, 1 inch of rain on 1,000 square feet of roof yields about 623 gallons of water. Even small storms can fill a 50-gallon barrel quickly. Plan storage accordingly and prioritize robust overflow protection. If space permits, linking two rain barrels at the same elevation provides 100 gallons of capacity without dramatically widening your footprint.
Fitment for 2×3 and 3×4 Downspouts
Most homes use 2×3 downspouts; larger roofs often have 3×4. Both EarthMinded FlexiFit and Oatey Mystic accommodate 2×3 downspouts out of the box. For 3×4 downspouts, follow the manufacturer’s instructions for the correct template, adapter, or cut-out. A precise, clean cut ensures the diverter seals well and directs water cleanly into your barrel hose without weeping at the edges.
Choose a Base and Elevation
A raised base improves gravity flow and makes hose or watering can use easier. Use a compacted gravel pad topped with concrete pavers, or a commercial barrel stand. Aim for 12 – 24 inches of lift while keeping the structure stable and level. Confirm that the barrel’s spigot will clear the stand and that you can access valves and fittings comfortably.
Tools and Materials
Gather everything before you begin. Many diverter kits include specialized bits or templates; check the box to avoid redundant purchases.
- Tape measure, marker, torpedo level
- Fine-tooth hacksaw or oscillating multi-tool (for downspout cuts)
- Tin snips (for minor trimming on aluminum downspouts)
- Drill/driver with hole saws per kit instructions
- Screwdriver set, nut driver set
- Adjustable wrench and pliers
- PTFE thread seal tape (Teflon tape) for leak-free fittings
- Silicone or exterior-grade sealant (as directed)
- Rubber grommets and bulkhead fittings (often included)
- Flexible hose and barbed adapters for linking rain barrels
- Overflow kit hose (AquaBarrel or similar) with bulkhead
- Safety gear: gloves, eye protection, hearing protection
Downspout Diverter Installation: Step-by-Step
Follow these steps for a neat, reliable install. Read the specific instructions for your EarthMinded FlexiFit Universal Downspout Diverter or Oatey Mystic Rainwater Collection System and adapt as they recommend.
1) Dry-Fit the System
- Set the first barrel on its final base. Confirm it’s level in both directions.
- Hold your diverter or collection head against the downspout. Mark the intended height of the inlet relative to the barrel’s upper third. This helps auto-shutoff functionality and proper overflow behavior.
- Ensure the hose can run downhill or maintain a gentle slope from the diverter to the barrel inlet.
2) Mark and Cut the Downspout
- For EarthMinded FlexiFit: Tape the provided template to the downspout at the chosen height. Mark the cut line.
- For Oatey Mystic: Measure and mark the length of the section to be removed. The Mystic head will replace this portion.
- Use a fine-tooth saw or oscillating tool for a clean cut. Deburr edges with a file or snips.
3) Install the Diverter or Collection Head
- EarthMinded FlexiFit: Insert the flexible port into the opening. Align the outlet with your barrel location. Secure per instructions with provided screws and gasket. Apply sealant only where recommended.
- Oatey Mystic: Fit the upper and lower halves around the downspout cut. Ensure the internal shelf points toward the hose outlet. Secure with screws and check for a snug fit.
- Attach the hose to the diverter outlet and route it to the barrel’s inlet port.
4) Prepare the Barrel Inlet
- Install the supplied grommet or bulkhead fitting into the barrel’s inlet hole. Many barrels have a pre-formed port near the top.
- Slide the hose into the inlet, ensuring a tight, kink-free connection. Use clamps on barbed fittings if provided.
- Confirm the barrel lid screen is seated to keep debris and mosquitoes out.
5) Set Up the Spigot and Base
- Wrap spigot threads with 4 – 6 wraps of PTFE tape. Thread into the lower bulkhead by hand, then snug with a wrench – do not overtighten.
- Ensure the spigot points forward and clears the base for easy access. Add a short leader hose if needed.
6) Test and Tune
- Simulate rain by running water into the gutter above. Check the diverter for leaks and verify water flows through the hose.
- As the barrel fills, confirm the diverter automatically returns excess flow to the downspout.
- Inspect all fittings for drips. Tighten clamps or add PTFE tape if necessary.
Linking Rain Barrels: Methods That Work
Linking rain barrels increases storage and balances water levels. The two most reliable methods are high-flow bottom linking and upper equalization via mid-height ports. Choose based on barrel design and desired performance.
Bottom Linking (High-Flow, Best for Equalization)
Bottom linking uses bulkhead fittings installed near the bottom of both barrels, connected by a short, large-diameter hose (3/4 inch to 1 inch). This method equalizes water levels quickly, reducing stress on overflow ports.
- Drill matching holes near the bottom of both barrels (above the lowest curve to keep a flat sealing surface).
- Install bulkhead fittings with rubber gasket inside the barrel and the plastic or metal nut outside. Hand-tighten, then give a quarter turn with a wrench.
- Connect with reinforced hose and barbed adapters. Use stainless clamps on both ends for leak-free fittings.
Upper Linking (Extra Buffer for Overflow)
Upper linking connects the barrels at or just below the top shoulder. It can provide extra buffer during surges but equalizes more slowly.
- Use factory ports if available. If drilling, follow the same bulkhead procedure as bottom linking.
- Route a hose between barrels, ensuring no kinks. Keep both ports at identical heights for consistent water levels.
One Diverter, Two Barrels
In most residential setups, one downspout diverter installation supplies the first barrel, and the link fills the second barrel. Keep both barrels level and at the same elevation. If you must place the second barrel slightly lower, place the overflow on the lower barrel to prevent reverse siphon.
Overflow Protection for Two-Barrel Systems
Even with a diverter, intense storms can exceed storage capacity. Dedicated overflow protection keeps water away from foundations and siding.
Installing the AquaBarrel Overflow Kit
- Choose an overflow elevation near the top of the first barrel – typically just below the lid.
- Drill the specified hole size for the kit’s bulkhead. Deburr the edges.
- Install the bulkhead with gasket inside. Hand-tighten plus a quarter turn.
- Attach the large-diameter overflow hose. Route it to a splash block, rain garden, or drain away from the home.
Best Practices for Overflow
- Use a large hose diameter to move water quickly during downpours.
- Direct overflow at least 5 – 10 feet away from structures on a downward slope.
- Add a screened elbow to keep out rodents and insects.
- In cold climates, make the overflow hose removable for winterizing.
First Flush and Filtration
A first flush device diverts the initial, debris-laden portion of a storm away from the barrel, improving water clarity and reducing sediment build-up. Some diverters (like EarthMinded) provide in-spout filtering, which helps, but a dedicated first flush improves results – especially under trees.
When to Add a First Flush
- You have a large canopy over the roof and frequent organic debris.
- You plan to use water for drip irrigation or micro-sprayers that clog easily.
- You want to reduce sludge accumulation and extend cleaning intervals.
First Flush Sizing Basics
Common guidance is to divert 0.02 inches to 0.05 inches of rainfall volume from the roof area feeding your downspout. For a 500 sq ft roof section, that’s roughly 6 – 16 gallons. A vertical first-flush tube with a ball valve at the bottom is simple to maintain – just drain it after storms or automate with a slow-release weep valve.
Ensuring Leak-Free Fittings
Good sealing practices prevent slow losses that undermine your collection efforts. The right materials and techniques make a big difference.
Threaded Connections
- Use PTFE tape on all male tapered threads. Wrap clockwise as you face the threads, 4 – 6 wraps.
- Snug connections until resistance; avoid overtightening, which can crack plastic ports.
- For straight threads with a gasket, tape may not be necessary – check the spec.
Bulkhead Fittings
- Install with the rubber gasket on the wet side (inside the barrel) for proper compression.
- Ensure the barrel wall is flat where you install the bulkhead – avoid ribbed curves that can cause gaps.
- Hand-tighten first, then a quarter turn with a wrench. Check after the first full cycle.
Hoses and Barbs
- Choose reinforced hose to prevent kinks, especially for linking rain barrels.
- Warm hoses slightly in hot water to seat fully on barbs; then clamp with stainless steel worm clamps.
- Periodically inspect for UV degradation and replace when needed.
Positioning, Leveling, and Safety
Water is heavy – about 8.34 pounds per gallon. A full 50-gallon barrel weighs over 400 pounds. Two barrels exceed 800 pounds plus the weight of the barrels and stand. Place your setup on compacted, level ground, ideally a small gravel pad with concrete pavers. Ensure children cannot climb the barrels and that lids are secure. Always use eye and hand protection when cutting metal or plastic.
Maintenance and Seasonal Care
Routine maintenance keeps your system clean, safe, and efficient. Build a simple schedule and prepare for winter to extend the life of your barrels and fittings.
Monthly or After Big Storms
- Check gutter guards and the diverter inlet for debris accumulation.
- Rinse the barrel screen and remove any visible sediment from the bottom via the spigot if possible.
- Inspect all leak points: spigot, bulkheads, link hose clamps, and overflow kit.
Algae and Mosquito Control
- Keep barrels shaded or use UV-resistant models like the Good Ideas Rain Wizard 50 or Ivy 50 Gallon Rain Barrel.
- Use tight-fitting lids and mesh screens to block mosquitoes.
- Consider mosquito dunks (Bti) if allowed locally; follow label instructions.
How to Winterize Rain Barrel
- Before freezing temperatures, drain barrels completely and leave spigots open.
- Disconnect the diverter hose and install the winterizing plug or bypass to return water to the downspout.
- Store hoses and small fittings indoors. If leaving barrels outside, turn them upside down or cover to prevent ice accumulation.
- Secure overflow hoses so they do not trap water and freeze.
Troubleshooting Guide
Water Bypasses the Diverter
- Cause: Diverter installed too low or misaligned in the downspout.
- Fix: Reposition per template. Confirm the internal shelf or flexible port points toward the hose outlet.
Barrels Fill Slowly
- Cause: Kinked hose, clogged screen, or partial blockage in the diverter.
- Fix: Straighten hoses, clean screens, and flush the diverter cavity.
Leaks at Bulkhead
- Cause: Gasket placed on the wrong side or over-tightening causing distortion.
- Fix: Reinstall with gasket inside the barrel; hand-tighten plus a quarter turn.
Overflow Near the Foundation
- Cause: No overflow kit or undersized hose.
- Fix: Add an AquaBarrel Overflow Kit and route 5 – 10 feet away to a safe area.
Case Study: Two-Barrel Setup with a 3×4 Downspout
Suppose your garage downspout is 3×4 and drains about 600 sq ft of roof. You choose the EarthMinded FlexiFit because it offers a neat in-spout installation with a universal template. You set the first barrel (Ivy 50 Gallon) on a 16-inch-tall paver stand and place the second barrel (Good Ideas Rain Wizard 50) beside it, perfectly level. Bottom-link the barrels with 1-inch reinforced hose and stainless clamps. At the top of the first barrel, install an AquaBarrel Overflow Kit and route it to a small rain garden.
During a 0.2-inch rain, the system captures roughly 75 gallons, leaving room for a bigger storm that follows. When a heavy thunderstorm hits, both barrels fill quickly, but the diverter returns excess water to the downspout and the overflow hose handles surges, keeping your foundation dry.
Downspout Diverter Installation Best Practices
- Use the manufacturer’s template for accurate cuts, especially on a 3×4 downspout.
- Keep hose runs as short and straight as possible to reduce friction losses.
- Place the diverter at or slightly above the top third of the barrel for proper auto-bypass.
- Seal only where instructed; over-sealing can trap debris and complicate maintenance.
Safety and Compliance Notes
- Always secure ladders and cut away from your body when trimming downspouts.
- Collected rainwater is non-potable. Label barrels clearly and keep away from children and pets.
- Check local codes and HOA rules regarding rainwater harvesting, overflow discharge, and mosquito control.
Cost and Time Estimate
| Item | Estimated Cost | Notes |
|---|---|---|
| EarthMinded FlexiFit or Oatey Mystic | US$25 – $55 | Includes hose and basic fittings |
| Two 50-gallon barrels | US$140 – $300 total | Brand and material vary |
| Linking hardware (bulkheads, hose, clamps) | US$20 – $45 | Higher for 1-inch reinforced hose |
| AquaBarrel Overflow Kit | US$25 – $45 | Choose larger hose for heavy rain regions |
| Base materials (pavers, gravel) | US$25 – $80 | Depends on existing site |
Most DIYers complete the project in 2 – 4 hours, longer if building a new base or adding a first flush diverter.
Step-by-Step Checklist
- Pick location, plan overflow route, and measure heights.
- Build and level a sturdy base for each barrel.
- Mark downspout and perform downspout diverter installation.
- Install inlet grommet, spigot, and screens.
- Link the second barrel (bottom linking preferred).
- Install AquaBarrel overflow and route safely away.
- Test under simulated rain and check for leak-free fittings.
- Create a maintenance calendar and plan to winterize rain barrel.
FAQ: Downspout Diverter Installation, Linking Rain Barrels, and Overflow
Can I use one diverter for two barrels?
Yes. Supply the first barrel from the diverter and link the second barrel. Keep barrels at the same elevation for reliable equalization. For very large catchment areas, consider a second diverter on another downspout.
What’s the difference between a 2×3 downspout and a 3×4 downspout for installation?
A 3×4 downspout carries more water and may need a larger cutout or adapter. Follow the kit’s specific template to ensure a snug fit. The installation steps are the same, but accurate sizing is more critical to prevent leaks on larger spouts.
Do I need a first flush device?
Not strictly, but it improves water quality by diverting the first, dirtiest runoff. If your roof sees lots of pollen, leaves, or bird activity, a first flush helps protect emitters and reduces sediment in barrels.
How do I prevent mosquitoes?
Keep lids and screens sealed, use fine mesh on overflows, and consider Bti dunks if permitted locally. Avoid open water surfaces. Check seals monthly.
How can I make fittings leak-free?
Use PTFE tape on tapered threads, install bulkhead gaskets on the wet side, and avoid ribbed areas when drilling. Tighten fittings hand-tight plus a quarter turn and recheck after your first heavy rain.
Where should overflow water go?
Direct overflow 5 – 10 feet away from the foundation to a splash block, swale, rain garden, or existing drain. Never discharge toward your home or a neighbor’s property.
Can I bury the overflow hose?
Yes, with a rigid conduit or corrugated drain pipe to prevent crushing. Maintain a continuous downhill slope and screen the termination point.
What about winterizing?
Drain barrels before freezing, open spigots, disconnect or bypass the diverter, and store hoses indoors. If leaving barrels outside, invert or cover them so ice cannot accumulate.
Is rainwater safe for edible gardens?
Generally, non-potable rainwater is fine for soil irrigation. Avoid foliar contact on ready-to-eat crops close to harvest and follow local guidance. Do not drink collected rainwater unless it’s filtered and treated to potable standards.
Can I paint my downspout after installation?
Yes. Use exterior metal paint suitable for aluminum or galvanized steel. Lightly scuff the surface and clean it before painting. Avoid clogging the diverter opening.
Conclusion: Confident Downspout Diverter Installation and Dual-Barrel Success
With the right plan, tools, and technique, downspout diverter installation is a straightforward weekend project. By linking rain barrels and adding robust overflow protection, you’ll capture more water, protect your home, and simplify garden watering. Combine a reliable diverter like the EarthMinded FlexiFit or Oatey Mystic with an AquaBarrel Overflow Kit and quality barrels such as the Good Ideas Rain Wizard 50 or Ivy 50 Gallon Rain Barrel. Finish with leak-free fittings, consider a first flush for cleaner water, and remember to winterize your rain barrel system. Your landscape – and your water bill – will thank you.