Ever since we saw a rain barrel in action at Matt & Kristin’s bungalow last fall, Sherry and I have been eager to collect our own otherwise wasted rainwater. We recently attended a local rain barrel workshop and are sharing a clear, practical rundown of what we learned.
Why install a rain barrel? Positioned beneath a downspout, a rain barrel captures roof runoff you can reuse for watering gardens and lawns, washing cars, topping off birdbaths or maintaining ponds. A 1,000-square-foot roof produces roughly 600 gallons per inch of rain, so even a modest roof can save a surprising amount of water (and money). Some people hook barrels to soaker hoses for automatic garden watering, too.
Rain barrels are straightforward to build, but sourcing a safe barrel is sometimes the trickiest part. Many pre-assembled barrels sell for $120 or more. We were happy to find a workshop that provided tools, instruction and a 50-gallon food-grade plastic barrel for $40. Ours had previously held olives, which gave us a chuckle — and made Sherry joke about being hungry.
The first step is drilling the faucet hole. Drill as low as practical so you can empty most of the water, but leave enough room to attach a hose or set a watering can beneath the spout. At the workshop a volunteer used a hole saw to make the opening in under 20 seconds while Sherry steadied the barrel.
With the barrel on its side, thread the faucet (hose bib) into the newly cut hole by screwing it in and back out once — this creates internal threads in the plastic. Use steady pressure so you don’t damage the plastic threads. After a quick trial threading, remove the faucet for the next step.
Apply a thin bead of caulk around the exterior edge of the hole to create a watertight seal:
Place a reducing washer over the hole with the raised lip facing the barrel. The caulk helps hold it in place. A reducing washer creates a neat, sealed transition between the barrel wall and the faucet threads.
Screw the faucet back into place over the washer. Because you already formed threads, this step goes quickly and should result in a snug, even fit.
Next, seal and secure the faucet from inside the barrel. This requires crawling into the barrel to apply caulk and fit the internal reducing washer, then tighten a locknut to hold the faucet assembly firmly. Bring a flashlight—the interior is dark—and gloves if you prefer. Pliers help make sure the locknut is tight and leak-free.
While one person stabilizes the barrel, the person inside completes the inner seal. At the workshop I ended up helping a few others tighten their locknuts, so don’t be surprised if you get drafted for extra barrel duty.
Optionally, you can install a rigid nipple near the top of the barrel as an overflow outlet to link multiple barrels. If you only need a single barrel, allowing overflow to spill over the top works fine.
The barrels from our workshop had 6″ holes already cut in their lids. To prevent mosquitoes and other pests, place a tight mesh screen over the opening and secure the lid. This keeps the stored water cleaner and deters insects.
After assembling the barrel, we transported it home and placed it under a discreet downspout at the edge of our driveway. Rain barrels aren’t typically curb appeal features, so we hid ours where it would be practical for Sherry’s upcoming back garden.
To direct the downspout into the barrel, we shortened the vertical section of the gutter by removing the elbow and cutting the downspout tubing to the appropriate height. A box cutter worked fine for trimming plastic tubing; once cut, we reattached the elbow and slid the barrel into place under the end spout.
Important safety note: place the barrel on level, stable ground. A full 50-gallon barrel can weigh several hundred pounds, so level the area with a shovel or compacted sand to prevent tipping. For now ours will fill gradually — we’ll do whatever rain dances are necessary to test it.
Have you used rain barrels? We’d love tips for first-timers as we start collecting water for the garden.