Earth shelters: Building an eco-friendly bunker

Photo: Shutterstock.com.

A bit of a departure from our usual fare, here’s something for the survivalist in all of us and especially for those folks lucky enough to have some land, preferably in a rural area. — Ed.

Most of us have a proverbial “plan-B,” or at least a rough idea of how we would protect ourselves and our families in the event of an emergency. As turmoil increases around the world, people are taking to bestsurvival.org to learn what equipment they will need to protect their loved ones and prepare themselves for what’s to come. Having a temporary safe haven is at the top of the list. However, before you start, you must know how the project is impacting the environment, as construction can leave a heavy carbon footprint if you don’t take the necessary measures to minimize it.

Fortunately, there are green and eco-friendly options available to you. In three phases, you can construct a sturdy, safe and environmentally-sound backyard shelter to protect you and your loved ones in case of an unexpected crisis.

Phase 1: The hole

This is the easy part. To build a shelter, the first step is digging a hole that is at least 10 feet deep-20 feet if you’re one to err on the side of extreme caution. Though it is possible to dig your own hole the old fashioned way (i.e. with a shovel and manpower), a more efficient means of moving that much soil would be to rent machinery like a backhoe or excavator. Doing so will turn days of digging into a Saturday afternoon project. If you’re not sure what sort of machinery you need for the job, why not hire excavator attachments to help you complete the project on time.

Phase 2: The walls

After clearing the space for your bunker, you have to reinforce it. Normally, this is where the construction of your shelter would negatively impact Mother Nature: the most common material used to line and seal structures is concrete, but traditional concrete is mixed with cement, making it an environmentally unsound material. Why? Three reasons: production wastes energy, it is fossil fuel-intensive, and its manufacturing is one of the top offenders of carbon dioxide emissions (aka greenhouse gas). Additionally, making cement requires aggregate materials like stone and sand from quarries, further depleting natural resources.

Luckily, fly ash, a by-product of power plants that burn coal, can be recycled and mixed with lime and water to form a cement-like material. AshCrete is another concrete substitute composed of recycled fly ash, borate and bottom ash. Use these alternatives for the interior walls and the floor of your bunker for a smaller carbon footprint than standard concrete. It would be sensible to paint the AshCrete walls with a water based sealer for concrete. This will coat the walls, protecting them in the process. A water based sealer looks natural and is environmentally friendly, so works for this project. Run a calculator for construction of a metal building and if you have the funds, reinforce the walls with steel. A shelter wall reinforced with steel has up to 20 times the compressive strength of an average cement wall.

Before you fill and slate, remember to leave openings for air filtration and waste elimination. You will need at least two air vents that exit at the surface. The vents can easily be concealed with foliage from the surrounding area. You’ll also require a filtration system and replacement filters, especially if you are planning to build a shelter to hold you and your family for months at a time.

Phase 3: The roof

The materials you use to construct your shelter’s roof will depend entirely on your needs. If security is first and foremost, a ceiling comprised of the fly ash composite used for the walls would certainly keep storms, trespassers and animals out, but if you plan to be in the bunker for an extended period of time, a green roof may be more your style. Green roofs – tiles made from organic, live greenery – offer excellent insulation, monitor temperature, and even soak up water during storms, which you can then filter for drinking water.

The above information is at least enough to get you started. By constructing an eco-friendly survival shelter, you ensure the safety of your family in case of emergency, while still respecting Mother Nature.

Jayme Cook loves DIY projects and previously worked in the home building and construction industry. Jayme studied writing in Wales, UK and is now an English instructor living in Phoenix, Arizona.

— Jayme Cook, Transition Voice