How do I Build a Simple Garden Shed?

Simple as it gets: build an adobe cabin/shed with framed door.

Turreted castle forts, many village houses, cabins and English-style cottages were originally made primarily from earth. Take advantage of the practicality, versatility and surprising ease of execution of this lowest-cost and simple-to-learn building material, also known as adobe or cob. By building a small structure such as a garden shed from earth, you can learn a time-honored, life-enhancing skill that could save you thousands of dollars in the future.

Things You'll Need

• Rocks or recycled cement blocks
• Shovel
• Mixing tarp
• Sand, clay or supply of any soil amendment needed
• 5-gallon buckets
• Bale of straw
• Plywood roofing sheets
• Roof support beams
• Rubber pond liner to fit over entire roof
• Oil/wax
• Silicone-based seal or glue
• Lumber for rafters

Instructions

1. 

   Earth-clay mortar can be used to embed/ mortar rocks for both foundation and walls.

   Place your wall foundation stones or blocks on top of a leveled patch of ground at the selected location of the shed. No mortar is necessary if your blocks are flat, like recycled cement, and if you do not live in a sensitive earthquake zone. Lay the foundation blocks tightly together like a jigsaw puzzle by staggering and overlapping the end connections of each rock or block. This is called a stem wall. Make the wall about 1 foot high. Measure and leave an opening where the entry door will be.

2. Spread the mixing tarp on the ground and load two or three buckets of earth into the middle. Test your soil for clay and sand contents before starting by shaking a cup of dirt in a mason jar filled with water left to settle. Examine the water to check for sand collected in the bottom and clay-formed clouds floating in the water that take a long time to settle. These two signs indicate sand and clay in needed amounts. If there is no sand in the bottom of the jar, or no long-hanging clay clouds formed in the water, you may need to add these ingredients.

3. 

   Earth-clay can be used as a mortar with hand-hewn bricks.

   Add what is found to be lacking slowly, along with water and straw, by tomping, twisting, mixing with your feet. Children can help with this task. Pull the tarp from the corners toward the middle and continue to mix and pull until your earth mix looks and feels like bread dough or a folded bean burrito -- thoroughly wet, but sticky and clay-like and ready to form with the hands. Mixing earth, sand and clay with water makes a bond between the clay and the sand. Load this mix onto your rock or stem-wall.

4. 

   Regardless of what it is -- fence, gate, church or garden shed -- anything small that can be sculpted from clay-earth can also be done big.

   Shape this mass so the earth hangs slightly over the rocks, making it so no water will slip under your earth wall.Keep loading the earth mix until your walls rise a foot or so above the opening for your door. Shape the earth up the sides of any window openings. Trim and smooth your earth walls as you go. Work the earth with your hands and fingers, and use a stick or tool to push the layers of earth together/into each other when you add new loads.

5. 

   Tulis in bundles are also used for roofing in some places. They are surprisingly waterproof.

   Embed any beams and rafters securely into the top of your walls. Place them to receive your roofing plywood. Nail these sheets down directly on top of them. Make sure your plywood framing extends a full 2 feet out over all of your walls. Shape the edges to please the eye. Glue a big sheet of pond liner down on the plywood as a water-repelling roof membrane. Reinforce with roofing nails, then give the nails a quick, complete dab of silicone seal. You can also trim this roof structure with 6-inch boards and fill with cardboard, carpet and 5 to 6 inches of soil for a durable earthen roof. For this, add a downspout.

6. 

   Two-foot overhang and white gypsum plaster make your little garden shed weather resistant and lovely to see.

   Pay special attention in the design stage. Spend extra time coating the whole earth structure with an oil and melted wax mix, brushed on in many layers, to waterproof and weatherproof the shed. Make your roof with a 2-foot overhang to protect all walls from weather and wet.

Tips & Warnings

• First make a 1:12 scale model of your shed, with 1 inch representing 1 foot.

• If windows and doors are desired, obtain them and embed any pre-nailed framing directly into the moist earth by sculpting it into place, then hanging the window or door on this frame by installing the hinges. Screw them onto the already-nailed-together frame.

• Use caution and the muscles of your legs -- not your back -- when lifting heavy rocks. Get white powdered gypsum at any hardware store.

References

• Living Earth Structures: Photos/Sheds
• House Alive: Cob Workshops
• The Cob Cottage Company: Workshops, Photos

Resources

• "The Hand-Sculpted House"; Ianto Evans, Michael G. Smith and Linda Smiley