How to Install a Rain Barrel for Roof Runoff

Rainwater is a high-quality, free resource that your roof is already collecting for you every time it clouds over. By integrating a rain barrel into your existing gutter system, you take the pressure off your local storm drains while keeping your garden hydrated with chlorine-free water that plants prefer. A system done well is watertight, filtered, and positioned to take advantage of gravity. Setting this up is straightforward, but the key is elevation and debris management. You want your barrel high enough to provide water pressure at the spigot, and you need a screen to keep out leaves and mosquitoes. When finished, you should have a reliable reservoir that fills during a storm and overflows safely away from your house foundation when full.

  1. Build a Stable Foundation. Clear a flat, stable area directly beneath your downspout. Lay down a bed of crushed gravel or paving stones to create a level, solid foundation that won't shift when the barrel is full.
  2. Elevate for Water Pressure. Build or assemble a riser for your barrel using concrete blocks or a heavy-duty wooden stand. Aim for at least 12 to 18 inches of height to ensure the spigot has enough clearance for a watering can or garden hose.
  3. Mark Your Cut Line. Hold your diverter kit against the downspout to determine where to cut. Ensure the diverter intake aligns perfectly with the barrel's inlet hose while leaving enough room for the barrel to sit on its stand.
  4. Saw and Smooth Edges. Use a hacksaw to carefully cut the section of downspout you marked. Remove the cut piece and file any sharp, burred edges so the diverter fits flush.
  5. Secure and Seal Tight. Insert the diverter into the downspout gap and secure it according to the manufacturer's instructions, typically using sheet metal screws. Seal the seams with exterior-grade silicone caulk to prevent leaks.
  6. Link Barrel to Flow. Attach the diverter hose to the intake port on the side of the rain barrel. Place the barrel on your prepared stand and verify that the hose has a slight downward slope toward the barrel.