…wood compound angle connection… by Spherical Geodesic Structures
…steel connectors with wood… by Spherical Geodesic Structures
…the manufacturing process…The substructure1. After clearing and leveling the home site, a trench is dug for the foundation footing, following detailed drawings supplied by the kit manufacturer. The base of the dome is not circular. Forms are placed for the footings; many builders like to use permanent Styrofoam forms that need not be removed. Concrete is then poured in the footing forms.2. A layer of sand may be used to further level the surface and provide a base for the foundation slab. Reinforcing steel bars are tied together in a grid, and concrete is poured to form the foundation.3. Foundation walls are built atop the footings, up to approximately ground level. If desired, riser walls (which are provided as part of the kit) are installed atop the foundation walls and bolted to one another.4. Floor joists are installed by standing wooden 2x12 (1.5x1.5 in [3.8x29.2]) boards 16 in (40 cm) apart above the foundation. The joists are nailed to a perimeter wooden frame and a wooden crossbeam. Three-quarter-inch (1.9-cm) thick plywood sheets are laid across the joists and nailed in place.The superstructureThe superstructure typically consists of 60 triangular panels. Depending on the desired size of the dome, the panelsare usually 6-10 ft (1.8-3 m) on a side. They may be prefabricated with the exterior panels installed, or they mayconstructed on site from precut lumber and metal connectors.If dome panels were supplied with the kit, they are set atop the foundation or riser walls and connected to oneanother in a sequence prescribed by the manufacturer. Until enough panels are connected to support themselves,they must be braced with poles radiating out from a block in the center of the floor. The following steps describe themore common case of frame erection followed by exterior panel installation:5. Base plates are installed atop the foundation or riser walls. These precisely beveled 4x6-in (lOx15-cm) wood strips provide a transition between the horizontal top edge of the walls and the slightly tilted triangles of the domes bottom strip of panels.
…the manufacturing process…6. Matching the color coding on the kits wooden struts and metal connectors, a triangle is formed and secured with bolts. The triangle is lifted into position and bolted to the wall and/or to the adjacent triangles. Successive rows of triangular elements are placed until the dome is completely formed. Because of their light weight, the triangles do not need supplementary bracing to hold them in place during construction.7. Wooden studs are nailed inside each triangle. Running perpendicular to one side of the triangle, they are placed about 16 in (40 cm) apart. If an odd number of studs is used, the center one is secured against a per-pendicular block near the triangles vertex, rather than extending to the vertex.8. Matching color-coded edges, the plywood panels are lifted into position on the exterior of each triangle and nailed into place. By working downward from the top of the dome, the worker can stand on the open framework below while attaching each panel.9. Vertical walls and roofs are framed for any desired extensions that will project outward from the dome. Plywood panels are nailed to the exterior faces of the extensions. Dormer extensions can also be erected for second-story windows.Finishing10. Windows, skylights, and exterior doors are installed.11. The roof is covered with rubber sheeting, and conventional roofing material (such as shingles or tiles) is applied.12. Conventional siding material (such as stucco or vinyl siding) is applied to the exterior of the riser walls.13. Insulation is placed between the struts and studs inside the dome and extension walls.14. Walls are framed to divide the interior into rooms. Conventional drywall sheets are cut according to patterns included in the kit, and they are nailed to the interior walls and the inside surfaces of the dome and riser walls. Because of the many angles between triangular sections of the dome, amateur builders often hire a professional to tape the drywall joints.