I attended the Texas A&M Agrilife extension class in Rainwater Harvesting on July 30 and came away enlightened and eager to build some rain barrels. The class cost $50, but for that you get a 55-gallon plastic drum to take home after listening to an informative lecture on the history and use of cisterns by Patrick Dickinson, the coordinator of the Urban Water program. As Dickinson showed slides of rain water collection systems from around the world going back to the Romans, I wondered why the great Southwest had come so late to this conservation method. He said it was because of the underground aquifers that long provided ample fresh water from wells. But those aquifers are now depleted and won’t be restored by normal rainfall for another 100 years.
What to do, other than move to Portland? One thing you can do, with the cost of water rising, is collect the water that comes off your roof when it rains. The volume is much greater than you might think. To figure how great, multiply the square footage of your house by .6 gallons for each inch of rainfall and then consider the result: a 1,500 sq. ft. home will generate 900 gallons of rain water for every official inch of precipitation. You would need 16 of these A&M rain barrels to collect all that. I decided to start with one, then I made two more. Ideally you need at least one barrel for every downspout coming from your roof gutter.
The benefits are at least threefold: 1) you collect free water to be saved and used on your landscape (through hoses) when it’s not raining; 2) you can prevent uneven drainage that plagues a lot of house foundations (ours, for instance) in North Texas; 3) you can help mitigate the massive storm runoff of chemicals and fertilizers washed from our lawns and driveways into rivers and streams.
It must be said that most rain barrels are not going to look as good on the outside of your house as a BMW parked in the driveway. You can purchase commercially produced barrels at Lowe’s or other home improvement centers, but if you get one of these basic drums from A&M (you have to take the class first) you can paint them pretty colors, put an image of Che Guevara on the side or sheathe them in wood to look more like a wine barrel or keg. The A&M-issue barrels are white plastic, and Dickinson said that a dark coating is essential (and black is best) to prevent sunlight from creating algae that can clog up the works.
After Dickinson’s hour-long talk, the class of 15 or 20 future rainwater harvesters moved outside, where all of us could pick out a barrel to take home, first making two basic additions — screwing into place the brass on-off spigots and pasting the nylon mesh filter over the 7-inch intake hole with silicone. We were given a handout with further instructions how to prep the barrels for use, including how to attach wooden staves, if desired. I suspect most people choose just to paint them, but what follows is my own variation on the wood option, using Western Red Cedar I bought at Cedar Supply in Carrollton.
You start with the challenge that the plastic 38-inch-high barrel is a rounded and tapered form while the wood slats are, yes, straight as a board. So, right away you know this is not going to be a real wood barrel where the staves (or slats) are steamed and bent at each end. Instead, we will glue the staves at a 90-degree angle to the two raised ribs that circle the midsection of the plastic drum, ignoring and hiding the underlying curvature. That’s a faux barrel, you say? Point taken.
Step 1. Spray-Paint the Drum with Rustoleum Primer and Paint black gloss ($5) in case the attached cedar slats do not all join seamlessly, forming a perfectly opaque surface.
Step 2. Cut the Staves to Size. Using a miter saw, I cut the staves to 39″, which will just hide the top rim of the plastic. The narrower the width of the stave , the better conformity to the lateral curvature of the barrel, but I decided to go with nominal cedar 1x4s, which at most lumber yards are actually 3/4″ x 3.5″ (at Home Depot they’re even more nominal — meaning less wood).
With true nominal (how else to put it?) lumber, the circumference of the barrel should require 21 staves, or a fraction less. You will likely have to “rip” or trim the last stave by less than an inch to fit tightly. This is best done on a table saw. You will also need to cut 1 stave 6″ shorter to accommodate the spigot.
To minimize waste, go to a lumber yard where you can buy 1x4s in 10′ lengths. You will get three staves from each 10-footer, so you need 7 of them. At Cedar Supply that comes to $38.
Step 3. Stain the Wood. I applied a Behr transparent cedar stain ($32/gal., used about 1/3). Grouping half the slats together at each end of a work table, I rolled the stain on — 2 coats for the exterior side and one for the rougher, hidden back side. To finish the ends and sides of the staves, I used a small brush.
Step 4. Attach the Staves. When the stain is dry, place the barrel upright on a flat surface and stretch 3 bungee cords around it, spaced evenly top to bottom. These elastic bands will hold the staves in place while the glue is drying.
Begin with the shorter stave that needs to be centered in place just above the spigot. Apply a gob of Gorilla Glue on both ribs at the spots where the stave will cross it, then slip the stave under each bungee cord and over the glue. You will square this “spigot stave” with the tops of the two adjoining staves once they are slipped into place on each side, which should be done next, pushing each full-length stave all the way to the floor or flat surface and making sure their contact with the spigot stave does not move it off center.
Also, this is the one stave that will not be held in register, so to speak, by contact with the floor, and it will possibly slip during the drying process from gravity. Just keep an eye on it as you’re inserting the other staves and pull it back up into line at the top as necessary. (By the time, you’ve got the other staves in, it should be fixed.)
Now, insert the rest of the staves beneath the bungee cords, progressing around the barrel, dabbing the glue on the ribs for each one. Gently press each new stave flush with the previous one so that it remains straight up and down. You can use a level to help with this, though the bungee cords get in the way of a precise reading. I didn’t find it to be much of a problem keeping the staves square as they went in. Make sure the smooth side of all the staves are showing.
When you arrive at the last space, measure its width, top and bottom, which you hope are the same — if the staves are in register. If not, you should be able to adjust them slightly, as the glue won’t be dry yet. My gap was 3.25 inches, which required trimming the last stave by 1/4 inch on the table saw to make it fit neatly in place, completing the circle.
Tips working with Gorilla Glue: It’s not only expensive ($16 for 8 oz.) but messy, and despite its apparent viscosity will drip down to the bottom of your staves and fuse them to the surface below unless you’re careful to keep jostling the barrel while the glue is drying. Most of the mess will be on the backs of the staves and not visible.
Step 5. Attach the “Decorative” Metal Bands
The curing time for Gorilla Glue is 30-45 minutes, but I waited at least an hour before removing the bungee cords for the project’s final step: attaching the steel hanger straps to further enhance the barrel’s resemblance to the real thing. I read somewhere that the metal straps are only for looks, but I would submit they are necessary to guarantee none of the staves will come loose and drop off, which, I assure you, can happen because bonding wood to plastic, even with this NASA-strength adhesive, is problematic.
Just to be safe, I would even leave the middle bungee cord in place while I attached the galvanized hanger straps, roughly binding the circle of staves together. You’ll need short (3/8 inch) wood screws and an electric drill. Hanger straps may not be the most photogenic component, but they have lots of holes for screws and come in a 25′ roll ($10.50) that should provide 2 bands for 2 barrels.
You want the band to be level all the way around, and one way to achieve that is to measure a distance (12″ for example) from the top on each stave and mark it with a crayon for reference as you circle barrel. You can also use a T-square, resting it on the top of each stave and pulling the metal band into place at the bottom of the measure as you go around. The straps are a bit unwieldy, and it’s good to cut a sufficient length off the roll and work only with that, rather than managing the whole roll (shown hanging in the photo).
Pull the strap as tight as possible and secure it with a screw, then another and keep moving. When you get all the way around, you might get lucky and be able to overlap the strap with itself, matching up a hole at the end with the one that held the first screw. If so, remove the original screw and re-screw it through the 2 overlapping holes, neatly completing the circle. If not, pull the band as close as possible to its beginning and simply screw it into place.
I used about 2 screws per stave — that’s almost 90 screws per barrel. They come in boxes of 100, about $3.
The barrel is now ready for deployment and only needs to be perched on a platform 12-18 inches high (4 cinder blocks will do), positioned so that its intake hole is under the downspout. The elevation will provide the water pressure necessary to disperse the contents.
Total cost of finished barrel, pro-rating the materials, was about $118.