Rural Builder - Summer 2010

sic designs are suitable for projects that might have to depend on volunteer labor, such as churches and schools.

Concerned about a lack of emphasis on art, parents in a school district in Cottage Grove, Ore., began exploring ways to raise money for an art teacher and art building. They were successful on both counts, although volunteers would have to do most of the construction work. Fortunately, one of the volunteers was general contractor Swearengin Family Construction in Cottage Grove.

Ground was broken in fall 2007. The concrete foundation was created with Amvic insulated concrete forms. Materials for a 61-foot diameter geodesic dome was supplied by Oregon Dome. Swearengin expects the building, which will boast 2,941 square feet of space, will be ready when school begins in September.

Total contributions for the project will come to about $150,000 in cash, time and materials, Swearengin said, including $37,000 for the dome kit, which also was paid by a donor. To have completed the project at prevailing labor rates would have cost at least $250,000, Swearengin said.

Why a geodesic dome? The lead donor wanted a unique building and enough space for creative activities. The dome answered both needs at an affordable cost.

Niangua, Mo., responded to a different set of problems to build a pre-school. Located in tornado alley, the community needed a shelter that would withstand the destructive force of extreme winds. By combining both needs, the small school district was able to obtain a grant from the Federal Emergency Management Agency (FEMA).

The solution was a steel-reinforced, concrete building by Monolithic Domes. It will cost $311,750, with 90 percent coming from the federal government. The school was expected to have been completed in March. The 2,941 square foot dome has a diameter of 61 feet.

The new building will enable the district’s preschool children to move from double-wide trailers — famous as tornado magnets — to a secure facility that keep 400 people safe from extreme weather.

An important side benefit will be the anticipated
energy efficiency of the building, according to David
South, president of Monolithic. A dome can cost as
much as 50 percent less to heat and cool, compared to
a conventional structure of the same size.

SCHOOLS, SPORTS AND SHELTERS

Gyms are especially well-suited for dual purpose school-and-community shelter functions.

The construction method for Monolithic Domes is as unusual as the buildings themselves, South said. The process begins with the placement of a ring beam footing and the pouring of a circular, steel-reinforced concrete slab floor. In many cases, a stem wall then is erected to give the building straight walls and a more conventional look.

Next, crews attach an Airform, a tarp made of tough, single-ply roofing material, which is inflated using giant fans. Once the Airform is inflated, work moves to the interior where treated wood is attached to frame the windows and doors. Three inches of polyurethane foam is then sprayed on the rest of the Airform, and a grid of steel rebar is attached to the foam.

In the final step, crews spray on a layer of shotcrete that ranges from 4 inches at the top to 8 inches at the base. The result is a permanent and virtually indestructible building, South said.

The durability of dome buildings is no longer in question, although some of its advantages can be seen as disadvantages. For example, the Chinese Alliance Church in Wheaton, Ill., was designed for 250 members when it was built in 1993. Although its paired domes — one for the sanctuary, one for a fellowship hall — have served the congregation well, according to the Rev. Danny Ma, the pastor, its acoustics are so good that they can become annoying. A whisper at one end can be heard clearly at the other end. Moreover, the church has grown to 400 members and is not quite sure how to expand the sanctuary.

But the congregation got exactly what it wanted when the church was built: a finished cost under $1 million (plus land), erection of the structure in one day, an exalted space with sight lines unrestricted by structural columns and a distinctive shape that has remained the talk of the community.