It's one of our most frequently asked questions: Do I need to strap rain barrels?
Californians, especially, may be wondering, due to the likelihood of earthquakes.
The probable answer is no. ARCSA/ASPE Standard 63, which lays the framework for most code standards related to rainwater harvesting (for those states that have adopted code at all), does not require strapping for rain tanks or barrels unless they exceed a 2:1 height-to-width ratio.
BlueBarrel's 55-gallon rain barrels are 35" tall by 23" diameter—well within the 2:1 guideline. The squat proportions, when full of water, will maintain a low center of gravity which mitigates the risk of toppling. If empty, barrels wouldn't do much harm if they were to fall.
That said, full barrels are heavy (a 55-gallon barrel full of water will weigh nearly 500 lbs!), so you may not want to take the risk. Strapping rain barrels will also help protect the under-plumbing on a BlueBarrel System™ in the event of tremors. School sites, like the one depicted below, may want to take extra precautions.
Luckily strapping is easy to do if you feel the need.
As usual, we have some recommendations:
1. Find the studs in your wall. In standard stick-framed buildings, you'll find a stud every eight feet. That's where you'll install your anchors for a solid brace. A BlueBarrel System requires a 2' x 2' footprint for each barrel, so with standard stud placement, you can strap groupings of up to four barrels.
2. Use a thick nylon strap. The internet at large will show images of thin metal straps used to strap rain barrels. We don't recommend this for a couple of reasons:
a. Metal-on-plastic is never a good idea. Especially if you live in a seismically active area, the metal will erode the plastic barrel walls over time, eventually destroying the barrel.
b. The stuff's so thin, what's to keep it from tearing right out of the wall with a 500-lb vessel pulling against it?).
Instead, use a robust nylon ratchet strap, available at most automotive stores. The nylon is exceedingly strong, and won't damage your barrels. Ratchets make for easy installation, as you can tighten the strap down after securing the anchors at the wall, and make adjustments over time if needed.
No wall studs? Perhaps your rain barrels don't line up with studs, or maybe you've installed away from the wall. Sink steel posts (eg. parking bollards) as an anchor.
Highlight from Cesar Chavez Elementary School
The 7-barrel BlueBarrel System above is at a school site. The school district did not want the rain barrels to interface with the building itself, so the post solution made sense in this case. The precaution of strapping seems to make perfect sense at a school site, or any area where children play. As you can see, you can strap more than four barrels together if you are not limited by building studs.
By the way, there's another cool hack we can point out with this installation. The school district also did not want to disrupt the existing drainage from the school roof. Do you notice there are two downspouts in the picture? Because a BlueBarrel System will easily fill with just a small portion of the runoff that comes off the classroom roof, we didn't need the full capacity of the industrial-sized spouts on this building. We installed a standard residential 2x3" downspout just upstream of the existing 3x4" downspout. The smaller downspout diverts rainwater into the BlueBarrel System. When the smaller downspout is overwhelmed, any excess water will continue down the gutter to reach the original downspout at the end of the line. No impact to the existing drainage system!