NOTE:
In my case, I knew we wanted a 2 barrel design, the same plan can be followed for a single barrel design. Modifications will be noted throughout the instructable.
Remove these ads by
Signing UpStep 1: Out Flow Parts List
2 2" DWV MIP Adapter - $0.90 each
2 2" DWV Street Elbow 90 degree Spigot x Hub - $2.01 each
1 2" PVC Pipe (2' section pre-cut) - $2.21
2 2" PVC Tee - $2.49 each
2 2" x 1-1/2" PVC Drain Waste Vent Flush Bushing - $0.86 each
2 1-1/2" x 3/4" PVC Schedule 40 Bushing Spigot x FIPT - $1.27 each
2 3/4" Short Galvanized Nipple - $0.98 each
** I chose not to use this but instead got the PVC schedule 80 (gray) equivalent from my local Ace Hardware for $0.79 to prevent as much metal in the design as possible.
2 3/4" PVC Ball Valve - $2.94 each
2 3/4" MPT x 3/4" MHT adapter - $3.53 each
** While my local Ace Hardware did have this piece in plastic for less, I chose to go with brass here to better withstand contact with the metal threads on my hoses.
1 can of PVC primer and cement - $6.96
NOTE:
For a single barrel design you do not need the Tees or the PVC pipe. You have the option to change the 90 degree Street Elbow with the 45 degree Street Elbow to reduce the bend of an attached hose.







































Visit Our Store »
Go Pro Today »




I'm about to build my rain barrel system and I'm a bit torn and to which system to go with.
1. The overflow at the top fills the next barrel (one barrel could be full and the next could only be half full)
2. They connect at the bottom and all fill evenly at the same time.
My question is, does one style/system have a benefit over the other?
Will one system deliver more pressure than the other.
Thanks in advance
A full barrel will have a higher head pressure (0.43 PSI per foot of "head", or level of the water above the level of the discharge) than a mostly-empty barrel.
In my system, I have a single fill from the gutters in the lead barrel, a common header connecting the underside of all the barrels, and a valve between each barrel on the common header. I have an extra valve at each end of the common header - one valve is attached to my discharge hose (for using the water). The other valve is in place for draining the tanks as well as to provide future expansion by adding more barrels.
Thank you
Gafarmboy
They use them for cleaning chemicals.
My only question is why did you decide to put two ball valves for outflow on your system versus one? I had planned only one but I'm interested to hear your experience before I commit either way.
With two spigots I can leave a hose attached for regulary watering of the garden plants and have a spigot available for filling a watering can or other container there at the barrels. You could use a Y splitter, but again that reduces the volume. Once I settled on using the 2" diameter PVC, that freed me up to have two separate spigots that do not have to "share" the piping leading to the spigot.
How can water coming into your barrels in a 5/8 line compete with the pressure of the rising water to completely fill the barrel???
I understand the skepticism. I tested the theory myself first with a watering can and then with our purchased, top-loading, rain barrel before building this.
The key to it is gravity. Water will always find the lowest point and settle there. As an illustration, think of your standard 2 gallon watering can. Even though the total volume of water in the can far exceeds the volume of water in the spout, it does not push the water out of the spout. Instead, gravity pulls it all to the bottom. The water comes out of the spout only when the spout is lower than the level of the water. Likewise, this design fills my 110 gallon "watering can" through the spout instead of through the opening at the top. With the diverter positioned in the downspout so that it is level with the top of the barrels, I gain the maximum capacity. The point to keep in mind is that the diverter is the true entry point to the storage system, not the connection point of the hose to the barrel.
A key to a successful implementation is the drilling of the air holes in the top of the barrel(s). This releases the air pressure in the barrels. Without them, when the air pressure inside the barrels is greater than the gravity-driven water pressure coming in through the tube, the water will build up in the supply tube and then go down the downspout. With the air holes, it fills and empties beautifully.
It is noted in steps 3 and 4 that I have simply used pipe thread tape and a rubber mallet to tap the joints together securely. While there are a few drips now and then, it gives me the flexibility to adjust the angle of the spigot assemblies (different heights for watering cans, buckets, water guns) and also to take the entire outflow assembly off and inside for the winter (your second question).
I did look into adding another section of 2" PVC pipe to the 2" DWV MIP Adapter and another section of 2" PVC pipe to the DWV Street Elbow 90 degree Spigot x Hub and then using a 2" to 2" Flexible Drain Coupling ($4.33) to connect them. This would allow for the whole thing to be cemented and yet portable. I chose not to do this because it would make the entire outflow system much bigger. In order to compensate for that I would have needed another four concrete blocks. The cost of the couplers and blocks would have added another $10 or more.
There is also the option to replace the PVC 90 degree elbow with a 2" Flex Quik Elbow ($7.66). Again, they are significanly more expensive than the PVC elbows ($2.21) but it would be a tight seal.
I know that I commented on this before but I since I decided that I am going to build this I need something from you. I was just wondering how long is this setup from the edge of one barrel to the edge of another.
-Jake