You can build a stone slip form structure, which is becoming popular as an economic and attractive alternative method of homebuilding. Little by little and at your own pace you can complete a sizeable building. Before building slip form walls, you should already have a floor plan, building permits and a foundation to build on. The amount of each building material will be determined by the size of your forms and building.
Collect stones in nature, ask farmers for unwanted stones or buy them at a stone yard. Buy plywood sheets, 2-by-4 lumber and screws at a lumberyard, and cut the plywood forms to the desired dimensions. Typical slip forms are about 18 inches high and 4 feet, 6 feet or 8 feet long.
Cut 2-by-4-inch lumber to build a pair of rectangular, structural frames using 2 1/2-inch screws. Attach one plywood sheet to each frame using an electric drill and 1 1/4-inch wood screws. Attach vertical 2-by-4 supports within the frames every 2 feet. Drill 1/4-inch holes through the centre of each vertical 2-by-4 for wire-laced bracing.
Mount the frames. Cut 1-by-2-inch wood spacers 12 inches long for a 1-foot-thick wall. Prepare one spacer for every 2 feet of wall length. Place the wood frames vertically on the footing.
Place a spacer at one end of the frame as you lace a doubled wire through the 1/4-inch holes to draw the walls together. Wrap the wire around nails and twist the nails to tighten the walls together. Repeat this process on every vertical 2-by-4. Nail 2-by-4 bracing every 2 feet along the top and sides of the frame and hammer pegs into the ground at the base of the wall to keep it from moving.
Mix concrete according to the manufacturer's directions. Place flat stones one by one along the inner face of the wall with the flat side of the stone against the plywood. Use a bucket and trowel to add concrete. The concrete should have a consistency such that it holds stones against the form but also flows and forms together well. Keep adding stones and concrete until the entire form is filled.
Remove the forms after the concrete has set, then brush off and clean the stones. Fill any gaps with concrete. Use 2-by-4 bracing at a 45-degree angle to support slip forms at upper levels. On the outside wall surface, apply waterproofing sealant and foam insulation panels if desired.
- The screws will penetrate more easily if you use a 1/8-inch drill bit to first pilot drill the holes. Paint both sides of the slip form with a waterproofing coating to keep the concrete from sticking to the wood. Painting only one side may cause the boards to warp.
- Buildings generally require building permits before construction. Check your municipality's building code for specifications for required footing sizes, steel reinforcement and all other details.
- Wear a mask when mixing concrete powder. Wear gloves while working with wet cement.