Stone age to space age shelters, Roundup, MT has both (Part 2)

I wrote about the rock houses outside Roundup, Montana in Part 1 of this two-part series. But the first building that really caught my eye in town was the "blue dome-shaped building" that sits on the south side of US 87 just before the highway curves south toward Billings. That building is the topic of Part 2 of the series.

When I first started inquiring about the history of the structure I referred to it as "a geodesic dome." Back in the late sixties Buckminster Fuller was on the faculty where I attended college. A world-renowned architect, he first promoted the utility of geodesic domes. The building in Roundup looked to my untrained eye like a geodesic dome. Looking for information about the domed building I was given the names of Pete and Norma Kolnikov. They built the blue dome in town and, thirty years ago, built the monolithic dome they still live in outside Roundup.

Pete Kolnikov explained a geodesic dome is made of a combination of shapes while a monolithic dome, like the blue building, is constructed in one piece. Monolithic Constructors' website has an eight-minute video that tells the story of the monolithic dome, its growth in popularity and generally how the building process works. The guy who is credited with coming up with this successful construction process concluded the geodesic domes of Buckminster Fuller had many drawbacks.

Thirty years ago Pete and Norma Kolnikov built the monolithic dome where they still live

I visited with Norma Kolnikov by phone about the monolithic dome she and Pete built outside Roundup. Asked, "How did you decide to build a monolithic dome for you, Pete and your family?" Norma laughed and said, "We planned to move to Montana and build a terra-dome house (that's a house covered with dirt). Turns out the ground in Montana was too rocky for a terra-dome structure." They saw a magazine ad for monolithic domes and the rest is history.

Building a monolithic dome starts with a concrete slab, then an airform (like a giant balloon) is custom manufactured off site using architectural material. The airform is laid on the slab and inflated. Then various layers of materials, along with rebar, are applied to the interior of the airfrom. The airform stays in place as an exterior protective layer. Once hardened the dome's shell is completed.

Norma Kolnikov shared some observations about building a monolithic dome structure

The Kolnikov's dome has four bedrooms plus two bathrooms, an 'open' kitchen and other living/storage space. The dome's footprint is 100 by 32 feet. "The first challenge," Norma shared, "was to build the four connected slabs needed to support the airform. These were all round and had to be to exact size to accommodate the airform we had on order." Norma admitted, "I relied on my high school geometry and hoped we had all the measurements correct."

The airform arrived as one continuous piece and weighed 1,000 pounds. Once the airform was in place a grain drying fan was used to inflate the form. Pete sprayed the first three-inch layer of urethane that coated the interior of the dome. Once the urethane dried rebar was added to strengthen the dome.

The last step was to spray a layer of shotcrete to create the inside interior finish. The Kolnikovs hired that work done. Norma said, "The people who did the spraying did not do a good job and Pete spent several months sanding and patching to get an acceptable interior finish." She added, "Applicationof shotcrete has improved since we did our dome."

I'd read that the cost to build a monolithic dome was about the same or slightly more expensive to build than a conventional structure. Norma explained, "In our case it was cheaper to build the dome since we did a lot of the labor ourselves. Still, I think the cost to build either type house with hired labor would be about the same."

So what are the advantages and disadvantages of monolithic domes? Most experts say maintenance costs are significantly lower for monolithic domes. The lack of seams makes a monolithic dome easier to maintain as well as more efficient to heat and cool. A single unit is better able to withstand severe winds, regularly surviving hurricanes. Norma commented, "A few years ago we had a pretty severe hail storm. The dome wasn't affected but you could sure see where the hail damaged the vehicles sitting outside."

There are some disadvantages. The rounded structure can result in difficulties placing furniture near the sloped walls. Oddly shaped rooms can cause wasted space in narrow corners. The odd appearance of a monolithic dome house can make it hard to sell. And the nature of the rounded base means more land space may be needed than for a conventional structure.

In the late 1990s the Kolnikovs built the blue monolithic dome in town for use as a coffee shop. That structure is 35 feet in diameter with a wall across the east end to create a bathroom and storage area. The building is now owned by a local accountant who uses the space for her business. She and her daughters operated a coffee shop until the daughters left home as adults. She plans to keep the space for her business but admits "there may need to be some minor adjustments to make it more functional as office space."

So there you have it. The area in and around Roundup has some interesting examples of both stone and space age housing. In case you're thinking about moving to a cave or living in a dome, there are definitely lessons to be learned from folks in and around Roundup.