Having portable shelter in your backyard is a convenience many people would enjoy and it's not as difficult as you might think. You could even double the portable shelter as a root cellar. It's like having your own private supermarket in your backyard. In an emergency you could shelter your family for a few hours, a few days, or even a few weeks if necessary and you'd have a fresh supply of fruits and vegetables to eat.

A good dual portable shelter & root cellar should provide cool, above freezing temperatures and good circulation of moderately humid air. The combination root shelter and portable shelter described here naturally has those features. The dirt floor takes advantage of the naturally cool, even temperature of the earth. It also reduces costs and provided humidity.

The walls are durable and sturdy. In extreme climates, the remaining cores can be filled with loose insulation to keep temperatures more even. The walls are topped by a wood frame made of 2 x lumber. The roof is protected by sheathing, roll roofing, and plastic film, then covered with 2 feet of soil. The cellar is vented for good air circulation, and a drainage system protects the interior from water seepage.

The ideal location for your combination portable shelter and root cellar is on a hillside or slope facing away from prevailing winds. If the cellar is so located, you may find you won't need a stairway. Even without a slope, choose the highest ground you have for the best drainage possible. Avoid any low-lying areas unless you want to run the risk of your cellar filling up with water in the spring.

The materials required to build this portable shelter cost about $1,200 which may sound pricey but not if you amortize those costs over the expected 20 year lifetime of the portable shelter...and you'll have a root cellar to boot.

If you're looking for ways to cut costs even more, it can be done by making the most of any materials you may have or can buy cheaply in your area. Remember, with regards to a root cellar, you shouldn't be interested in appearances. The most important consideration for your portable shelter is size and strength.

All the lumber should be pressure-treated or treated with a wood preservative such as copper naphthalene which is sold under various brand names. Wood should be soaked in the liquid if possible or generously painted with the solution in accordance with the manufacturer's recommendations. Be prepared to store all materials under cover to keep them as dry as possible before and during construction of your portable shelter.

The time required to build your portable shelter depends on the dimensions of your portable shelter building design and the size of your crew. You could finish over the weekend or it may take a few weeks. But regardless of how long it takes, you'll have an inexpensive, sturdy portable shelter and root cellar that will provide around two decades of use.