How to Measure for a BlueBarrel System

While it’s fun to calculate how much water you can catch from your rooftop, most roofs will generate an astronomical amount of runoff. (Every inch of rain falling on a 1000 square-foot roof area generates over 600 gallonsthat’s 11 standard sized rain barrels!) Most people are constrained by space, so dimensions are often the most helpful way to size a system.

Barrel and System Dimensions

Each barrel in a BlueBarrel System™ requires a two-foot by two-foot (2′ x 2′) footprint, often along a wall or fence. The “Multi-Row Connection” available in our online store allows for double (or triple) rows of barrels if your space is suited for a block rather than a row.

Barrels are 35″ tall, and with our simple recommended cinder block foundation, the complete BlueBarrel System height is 3′ 7″. (You may elevate your system more if you’d like, but work with a competent builder to ensure a safe elevated structure. Each barrel will weigh about 500 lbs. when full!)

BlueBarrel Foundation

A basic foundation consists of two standard 8″ x 8″ x 16″ cinder blocks under each barrel, with each set of cinder blocks placed at 2′ (or 24″) on center from the last set. (Details are included in the illustrated instructions that come with your RainKit, and in our How-To Video Series.)

foundation blocksFor example, if you are installing five barrels, you will need to clear a 2′ x 10′ area. For ten barrels, you will need a 2′ x 20′ space.

Notice the placement of windows, crawl-spaces, electrical boxes and other access points you don’t want to block off. You can customize your installation by leaving extra space between barrels if necessary.

If you have a flat stable surface to build on (e.g. concrete or asphalt pathway, or well-built deck), the cinder block foundation can lay directly on the ground. If your area is bare soil, we recommend adding a few inches of compactable base rock (also known as “crush,” “crush base rock” or “road base”) for a level and stable footing under your foundation. Read more about how to prep your site for a BlueBarrel System here

In most cases, the space you have available will determine the size of your BlueBarrel System, but check out our other sizing tools to estimate how much water you can catch and how much you’ll use!


NEXT: order your rainkit



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