The barrel is essentially a sturdy wood shell built around a repurposed plastic garbage bin that serves as the reservoir. Made of rot-resistant lumber, the barrel goes together with easy lap and butt joints and some deck screws. Decorative exterior battens dress it up, and you can customize them and paint the barrel to fit any style of house or garden.
Follow along as This Old House contributor Christopher Beidel, owner of Pernt, a handmade-furniture company in Brooklyn, New York, leads you through the simple steps it takes to green up your garden.
How to Build a Rain Barrel: The Overview
SATURDAY: Assemble the box (Steps 2-13).
SUNDAY: Install the bin, attach the diverter, and make the connections (Steps 14-18).
- 1x6 pressure-treated vertical slats: sixteen @ 40 inches
- 1x6 pressure-treated lid slats: four @ 23⅞ inches (cut to fit)
- 1x6 pressure-treated floorboards: four @ 20⅞ inches (cut to fit)
- 5/4x4 pressure-treated interior battens: four @ 23⅞ inches
- 5/4x4 pressure-treated interior battens: four at 20⅜ inches
- 5/4x4 pressure-treated lid battens: two @ 18⅜inches
- 1x4 pressure-treated decorative battens: two @ 23 inches (cut to fit)
- 1x4 pressure-treated decorative battens: two @ 24⅜ inches (cut to fit)
- 1x3 pressure-treated decorative battens: four @ 23 inches (cut to fit)
- 1x3 pressure-treated decorative battens: four @ 24⅜ inches (cut to fit)
- 4x4 pressure-treated legs: four @ 10 inches or customized to your terrain
- DIY Rain Barrel Construction and Installation Kit with Downspout Diverter: one; Rain Brothers
- Black 35-gallon square trash can: one
- ¾-by-3-inch brass nipple: one
- 5¾-inch black door pull: one
Steps for Building a Rain Barrel
Step 1: Cut the slats and battens
On a miter saw, cut to length the 1x6 vertical slats for the barrel. Also, cut the 5/4x4 interior battens.
Step 2: Assemble the parts
- Layout four 1x6 slats on your work surface. Place ⅛-inch spacers between the boards, and clamp the assembly together. The interior battens sit 5½ inches from the top and bottom of the slats.
- The pairs of battens for two sides are inset 1¾ inches on either end to allow space for the battens of the other two sides, which run flush to the edges of the slats.
- Secure the battens with 1½-inch deck screws. Make the other three sides the same way.
Step 3: Assemble three sides
- Set two bar clamps on your work surface, and place a side with the flush battens between the jaws. Stand the two sides with inset battens into the clamps and tighten the assembly.
- Use a ⅛-inch bit in your drill/driver to make pilot holes along the corners—through the face of the slats of the upright sides and into the edges of those on the flat side, as shown. Secure the edges with 1½-inch deck screws.
Step 4: Add the last side
Loosen the clamps, and stand the assembly up on your work surface. Set the fourth side in place, as shown. Drill pilot holes, and screw it to its adjoining sides.
Step 5: Install the floorboards
- Measure the dimensions of the interior, just above the lower battens, to get an accurate length for the floorboards. On your miter saw, cut four 1x6 pieces to length.
- With the box on its side, place a floorboard against the top edges of the lower battens, and secure it with 1½-inch deck screws, as shown. Install the other three floorboards.
Step 6: Cut the legs
On your miter saw, cut 4x4 lumber into the four legs that will support the box. You can make these leg pieces shorter or longer if the surface where you will install your barrel is sloped or irregular.
Step 7: Install the legs
- Use a piece of 5/4-inch scrap to keep one leg level at the corner, and butt it up against the floor. With a ⅛-inch bit in your drill/driver, make two pilot holes through the slat and batten of the side and into the top portion of the leg.
- Drive 2-inch deck screws through those holes and into the legs. Repeat the process on the other face of the leg, then install the other three legs.
Step 8: Cut the boards
On a miter saw, cut the 1x6 lid slats and 5/4x4 battens to fit. Lay them out on your work surface, with ⅛-inch spacers between the slats. Clamp the assembly together. Place the battens 2 inches from the sides and ends of the slats. Drill pilot holes, and fasten the battens in place with 1½-inch deck screws, two in each slat in an offset patten.
Step 9: Install the door-pull handle
Flip the lid over. Center the handle on the lid. Use your drill/driver and the fasteners that came with the handle to secure it.
Step 10: Layout your design
Use your combination square to transfer level lines around the barrel to make sure the ends of the battens meet correctly at the corners.
Step 11: Layout your design
- On your miter saw, cut to fit the battens for the decorative bands on the exterior of the barrel. The top band is made of 1x4 boards; the bottom two bands are 1x3. (Of course, you can choose any pattern you like.)
- Remember that two boards of each batten band are longer than the other two to allow for overlapping butt joints at the corners.
Step 12: Attach the battens
- Set the barrel on its side on your work surface with 1-inch scrap underneath. Put a bar clamp over the top to hold a batten in place.
- Use your drill/driver with a ⅛-inch bit to make pilot holes, then secure the batten with 1 ¼-inch deck screws. Repeat the process on the other battens on that side.
- Rotate the box on the work surface and repeat the process on the next side, and so on, until the bands wrap completely around the barrel.
Step 13: Make the inlet
- Put the plastic bin inside the barrel. With a ⅛-by-3-inch bit in your drill/driver, make a hole through the barrel wall and through the bin so that the hole ends up 1 inch below the plastic rim. (Go through the middle of a slat.)
- Then, with the kit-supplied hole saw in your drill/driver, follow the pilot hole and cut through the barrel.
- Remove the bin and make a matching hole in it, using a scrap block inside to protect your hand.
Step 14: Make the outlet
- Put the bin in the barrel. On the opposite side, use the same bit to drill a pilot hole through the barrel wall and the bin about 2 inches above the bottom of the bin.
- Remove the bin. Put the smaller, kit-supplied hole saw in your drill/driver, and, using the pilot hole as a guide, make matching holes in the barrel and the bin.
- Insert the threaded rubber grommet into the hole in the bin, as shown.
Step 15: Install the hose bib
Since the walls of the bin slope away from the barrel, we attached the hose bib to a ¾-inch-by-3-inch brass nipple to bridge the gap. The nipple runs through the barrel and threads into the rubber grommet in the bin to make a water-tight connection.
Step 16: Cut the downspout
- Measure the finished height of the inlet hole in the barrel. For proper flow, locate a spot on your downspout 1 inch higher than the inlet.
- Using the kit-supplied hole saw, drill a hole in the downspout. Watch the sharp edges, and wear gloves when you insert the diverter valve. Set the barrel in place.
Step 17: Connect the flexible hose
The kit comes with a length of hose. Insert one end of the hose into the diverter valve and the other through the barrel and into the inlet. Now, do a little rain dance.
Tip: Cover the top of the plastic bin with landscape fabric or window screening to prevent mosquitoes from breeding in the water.
Gutter connection: DIY Rain Barrel Construction and Installation Kit with Downspout Diverter, $33; Rain Brothers