I went to a Master Gardener workshop where we learned how to make a rain barrel and how to figure out how much rain we could collect off our roofs. The formula for figuring out how much rain comes off our roofs is easy-take your sq footage of roof x .623 gallon x how many inches of rain. For example: 2000 sq ft roof x .623 gal=1246 x ½” (.5) of rain=623 gallons of collectible rain. It’s amazing how much rain we could gather assuming of course we get some rain!
Here’s how we build a rain barrel. First we started with some food grade 55 gallon rain barrels.
Here is the list of what you will need:
¾ “ bronze or brass water faucet
(1) ¾ inch plastic hose to pipe fitting
(2)- ¾ inch flat rubber washers
(2)- ¾ inch galvanized metal washers
short hose for the overflow
3” hole saw (optional)
7/8” drill bit/router
1. Put barrel on its side and measure about 3 inches up from the bottom.
2. Drill a hole with your 7/8” bit. Making sure you are drilling straight up and down (no angle). When the faucet is attached to the bottom of the barrel, you should have enough room to attach a hose and still have the barrel sit flat.
3. You may want to take a knife and ream out the hole beveling it a little wider on the top so you can start to screw the faucet into the hole more easily as it is a tight fit.
4. Now screw the faucet into the hole to start the threads then back it out. This makes it easier to screw back in after you put the washers on the barrel.
5. Put marine glue around the hole.
6. Then put the ¾ inch black rubber washer and the metal washer on top of the hole. Make sure the black rubber washer is the washer that goes against the barrel first. Take the faucet and screw it back into the hole. The faucet will cinch down on the metal gasket and tighten the rubber gasket against the barrel. The hole should be very snug or it will leak. You may have to use pliers to get it screwed in all the way.
7. Afterwards drill a 7/8” hole 2 inches from the top and as shown for the overflow hose to attach. Repeat steps above but insert the black plastic pipe-to-hose fitting through this hole.
8. It has small threads on one side and large threads on the other side for the hose to attach. In this picture the large threads are on the left and the small threads are on the right. Screw the small threads into the hole. The large threads fit a hose for the overflow.
9. There are several ways to drain water into the barrel.
a. Position it under a downspout or canale where the water flow can be directed into the barrel.
b. Use a rain chain to direct water into the barrel
c. Use downspout adapters like the black one above. The top of the barrel will most likely have a small covered hole that can accommodate the downspout adapter but if not you can drill a 3” hole on the top.
d. You can also cut holes to fit a basket that fits in the barrel like the one above.
10. Here is the rain barrel ready to be put under a downspout.
Put the rain barrel onto a base or cinder blocks where it will be level. It should be high enough to accommodate a pail or you can attach a hose to the end.
Lastly be sure you empty the barrel at the end of season and leave the faucet open so water will not freeze in it.