How Do I Build an Earth-Berm Garage?
- 1
Your drain pipe should emerge downslope and drain into an appropriate water channel.drainpipe image by ROSEYC from Fotolia.com
Dig a trench for under your planned walls. Dig this trench two feet wide by 18 inches deeper than your frost line, by the diameter of your planned garage. Dig a french drain field two feet out from your walls, all the way around, under the roof line. Place the french drain pipe at the bottom of this trench. Make sure it will siphon off any water that might try to gather under your walls or floor. The end of the drain pipe should emerge pointing down-slope. Fill both trenches with gravel. - 2). Lay the foundation stones or blocks on top of the wall trench gravel, or pour your cement stem wall on top of it. Mortar is unnecessary if your blocks are flat, like recycled cement, and you also do not live in an earthquake zone. For stones or blocks, place them tightly together like a jigsaw-puzzle to make your stem wall. Make the wall about 1 1/2 feet high (or up to your knees). Remember to measure and leave openings where any doors will be framed and installed.
- 3). Load two or three buckets of earth into the middle of your mixing tarp. Add soil amendments learned from reading your book, and test your soil before starting. Add them slowly while stomping, twisting, mixing with your feet while adding water and straw to the mix. Pull your tarp at the corners, toward the middle and continue to mix and pull until your earth mix looks and feels like a folded burrito. Mixing earth, sand and clay with water makes a bond between the clay and the sand. This creates a sort of dough that dries like a rock in the sun. Load this mix onto your stem wall.
- 4
Earth-rock wall combinations last centuries even when exposed to the elements.lonely walls image by John Sfondilias from Fotolia.com
Shape this mass so the earth hangs slightly over the rocks, making it so no water will slip under your earth wall. To berm directly against your garage, build the earth contact side from cement, stone or recycled cement blocks, instead of stopping with a short stem wall. - 5). Continue loading the earth mix until your walls rise about two feet above the hole of your garage door frame. Shape the earth up the sides of any planned window. If the window is large, place a beam above the window, embedded into the earth mix to spread the weight above the glass. 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 when you add new loads.
- 6). Embed the beams and add the rafters you will use to anchor your roofing plywood when nearing the top of your garage walls. Nail your roofing plywood directly to the top of the embedded roof beams. Nail a lip or frame around the edges of the plywood sheeting for a 6-inch-deep bowl that holds garden soil. Make sure your plywood extends a full 2 feet out over all of your walls.
- 7
Use an external plaster after smoothly coating and trimming your walls.fancy garage image by Aaron Kohr from Fotolia.com
Lay the rubber liner into the roof-boat frame. Fix your downspout to a corner or edge so it will handle any water runoff, sending it into the french drain field. Fill the liner with old carpet, then cardboard, then at least six inches of soil to form an earth-bermed roof that will last decades if properly fitted. Seed this roof with red clover or another useful garden cover crop.