What could be more appropriate for a potter, who makes a living off of shaping clay, than to have a house built of the same material, along with some sand shell, gravel and a touch of Portland cement.
Sue Walters’ home, under construction now on Johns Island, is likely the first rammed earth structure built in South Carolina in modern times.
“This all makes sense,” says Walters, who owns Palmetto Pottery in the City Market. “I’m a full-time potter. I know this medium. So why not have a house made out of earth?”
In a classic example of what’s old is new again, rammed earth is an ancient and universal construction technique, dating to centuries before Christ, that involves tamping a mixture of earthen materials into making walls, floors and foundations.
The technique is making a comeback as people seek more sustainable, longer-lasting and energy-efficient structures. The thermal mass of rammed earth reduces the need for air conditioning and heating. That environmental ethic, along with relative affordability, was a driving force behind Walters’ decision to be a local pioneer and give modern rammed earth a try.
Beyond sustainability, however, rammed earth is becoming architecturally chic in western North America, Australia and China.
“I can’t open up ‘Dwell’ or ‘Architectural Record’ (periodicals) without seeing rammed earth,” says April Magill of Root Down Designs, who specializes in natural building methods. “I’m seeing museums, retreat centers and big commercial structures (using rammed earth). It’s not just this little hippie mud hut idea. It should be seen as masonry and the banks need to recognize it for financing.”
Walters’ original plan when she bought 15 acres on Johns Island was to have a young organic farmer use part of it to grow food. All she would want from the deal was to be able to harvest a little for herself.
But where would the farmer live?
Walters considered putting an affordable, energy-efficient mobile home on the land. She could buy one for $38,000, but then friends chastised her about it.
“They said, ‘You are not going to put a single-wide on that beautiful piece of property,’ ” recalls Walters.
One introduced her to a local contractor, Joe Faust, who pitched the idea of a rammed earth home. Faust insisted he could build one affordably, within a range of $65,000 to $75,000, largely because he and a building friend, John Burnet, would do the labor-intensive work themselves.
Faust, a 32-year-old West Ashley native, has been working in construction for a decade and shared an interest in rammed earth with local architect April Magill.
When the opportunity presented itself with Walters, Faust and Magill were ready.
Magill designed a borderline tiny house, 690 square feet downstairs with a 200-square-foot sleeping loft, that was oriented on an east-west axis to maximize passive solar heating. The house, which faces a majestic live oak tree, also includes porches in the front and back.
Like any home, the home will have plumbing, electricity and appliances. And while it will have ductless heating and air and a wood-burning stove, the use of both is expected to be minimal. Interior rammed earth walls will remain exposed, but can be treated like any concrete walls that require masonry nails or screws when it comes to hanging pictures.
Part of the sustainable qualities of the house, which Faust expects to finish by June, is that many of the materials are being sourced locally, including the clay, sand, windows and lighting.
All involved seem to have labor-of- love attitude about the house.
“It’s such a fun project in so many ways,” says Walters.
Google “rammed earth” and the images that pop up are modern, architectural masterpieces in California, British Columbia in Canada, Australia and China.
But despite what’s happening in other parts of the world, presenting a rammed earth project to building officials with Charleston County presented some challenges.
Magill recalls making the call to a county inspector about the project, shortly after the historic flooding in early October 2015.
“He said, ‘You want to build a dirt house after what just happened here?’ And I said yes,” says Magill, adding that rammed earth has benefits that many still don’t understand. “It’s not going to rot. It’s not going to get funky (mold). And termites won’t eat it.”
Among the requirements the county required was periodic strength tests, which would have to meet a minimum of 200 pounds per square inch (the first wall came back at 800 psi) and getting a structural engineer to stamp it.
Magill tapped local structural engineer John Moore of 4SE, who compares the 2-foot thick walls to “low-strength concrete.”
“Structurally, I think it’s a pretty good wall,” says Moore. “It’s totally appropriate for a residence.”
Still, to ease concerns of building officials for tropical-force winds and earthquakes, Moore put in an ample amount of reinforcing bar, or “rebar,” in the design of the walls.
Magill thinks the walls may have been “over-engineered” with all the rebar, which has made Faust’s job of tamping the material more challenging, but that “it’s what we had to do to meet the permitting.”
County Business Services Director Carl Simmons says permitting the structure took more time than usual because staff had to research specifications and codes in other parts of the country, such as New Mexico, before giving its approval.
Because the Johns Island project familiarized the staff with the modern process of rammed earth, Simmons says future projects won’t take as long to permit.
Simmons called the material “soil cement” and that the process is not new in South Carolina, noting that archeological surveys done for the judicial center in downtown Charleston uncovered an entire building built with rammed earth.
Indeed, it’s not unprecedented construction in South Carolina.
Dan Beaman, a local architect with Cummings & McCrady, worked with local engineer Craig Bennett with 4SE in 2010 in effort to restore the historic Church of the Holy Cross in Stateburg, located near Sumter.
The church was built in 1852 with “Pise de Terre,” the French term for rammed earth.
It was the same method the church’s building committee chairman had used in building his house.
Beaman says rammed earth could make a comeback in the United States, but that costs could be a limiting factor.
“It’s rather labor-intensive because like the name says, it’s ‘rammed earth’ and it assumes you have a ready source of earth and labor,” says Beaman, noting that construction of the church and house in Stateburg used slave labor.
He, probably like a lot of building professionals and permit issuers, had questions about how to engineer modern rammed earth for hurricane-force winds and earthquakes.
Meanwhile, Magill and Faust hope that Walters home will help them break down the barriers to rammed earth construction in Charleston and South Carolina.
Even though the roof hasn’t been put on it, the house is generating a buzz in more progressive circles of Charleston.
“There are a lot people who want to come out and see the house. It’s something you have to come and see,” says Magill, noting that one couple on James Island and an individual in downtown Charleston has expressed interest.
Among the people that will be interested in rammed earth, she adds, are people suffering from sensitivity to chemicals.
“We don’t build breathable buildings anymore. We’re building these very sealed up envelopes and pumping air into it,” says Magill. “The air quality in rammed earth buildings is amazing. There’s no off-gassing. It’s very healthy air quality.”