Dave Wills has his head deep in a fermenting vat in the upstairs of his Oregon Trail Brewery. His voice reverberates from within and is nearly lost among the spraying hose, humming equipment, and the radio playing Primus. He is mentioning something about being from California and how adobe inspired him to build an earthen home many years ago.
Wills is a busy man. Somehow between managing his Christmas tree farm, growing hops, being a hop broker, and operating a brewery, he has devoted the time to building himself the first rammed earth house in the area. However, before the conversation can go much further, customers arrive seeking growlers for a party. They receive both his total attention and a free sampling of the Oregon Trail IPA.
To learn more about rammed earth and properly visualize the process of making his new home, a visit to Wills’ abode was in order.
Building with Earth
Adobe is one of the oldest known building techniques, and is a process at one time or another practiced in nearly every corner of the world. With the right mixture of clay, sand, silt, a binding material like straw, and the drying properties of the sun, humans can make walls that will last hundreds or even thousands of years under the right conditions.
Wills has elected to build a rammed earth house on his 15-acre property in the hills of nearby Tangent. Similar to adobe, rammed earth construction starts with forms like when pouring concrete, then a mixture of earth and Portland cement is added little bits at a time. After each addition, the mixture is pounded down – in this case using pneumatic tampers similar to a jackhammer. Once it sits for a couple days, the forms are removed and voilà.
“Then you have a wall that’s, well, it’s fireproof, it’s rot proof, it’s insect and rodent proof, it’s noise proof, and you don’t have to paint it,” explained Wills, “you just put a clear sealer on there and you’re done.”
Earth houses are known for having a high solar mass, or the ability to capture and hold heat from the sun. Since we live here in the Pacific Northwest where the sun is not always available, Wills placed used foil bags from his hop business packed with donated Styrofoam inside in the center of his walls for insulation.
“The heat coming from inside the house can actually hit this foil and reflect off, and then you have this foam insulation in here as well,” said Wills.
“I am using two forms of trash for my insulation and sequestering this foam and foil in the middle of the wall, so I am pretty proud of that.”
Trex wood, made almost exclusively from recycled materials and nearly rot proof, is being used for door and window frames. Under the floor will be a system of pipes pumping heated water warming the house when the sun is down. A rain capturing system will provide all Wills’ Christmas tree watering and fire prevention needs. To top it off, all the earth has come from a local quarry only two miles down the road.
Wills explained all of this between mixing the materials with his Kubota tractor, inserting bags of insulation, checking his plans, climbing up and down the wall forms, building new forms, wiring rebar supports together, and managing to serve his workers a tasty pre-lunch Oregon Trail IPA.
“Look,” he said over the thrum of air compressors, a frontend loader, and classic rock verses rolling out of the radio, “these walls are going to be here for hundreds of years…hundreds of years.”
First Things First
“That’s the thing about building a house, you have to take care of all the underground stuff first,” Wills said while screwing boards to a concrete footer.
Two years before the first walls went up, electricity and water pipes went down. However, even this step is putting the cart before the horse.
“First is the architecture drawings, then the engineer’s drawings, then there is the permitting process, then you get to do all the compression tests just to get to the point where you can start going for it,” explained Wills.
“Then you start digging ditches.”
In the ditches are 2-foot-by-2-foot concrete footers, on top of which the 8-foot-by-2-foot earth walls are erected. Before the forms and walls are completed, a skeleton of rebar is embedded into the footers to aid in long-term stability – specifically to be up to county earthquake codes.
“This is the first permitted rammed earth house in Benton County, but the permit people will generally go along with a design as long as it’s been engineered by an engineer,” said Wills.
“In the plans it says that I need to have a licensed rammed-earth contractor helping with the project, so that’s where John came in, because John has been doing this for over 25 years.”
John Richards has a rammed earth contracting business in Northern California where he makes garden and retaining walls, columns, and about one full building a year. Richards was also inspired by adobe architecture, leading him to the rammed earth industry where he has been ever since.
“Depending on the engineer, traditionally [with rammed earth] they have gone six or seven stories without any reinforcement,” explained Richards, “I think the highest modern buildings that I have seen are 20 or 30 feet.”
Richards explained that Wills’ walls are rated at 2,000 lbs. per square inch. At 2 feet thick, he says you could go pretty darn high including multiple floors. That is, if you wanted multiple floors.
“This is designed to be no stairs in the entire house,” said Wills, “when I’m 80, 90 years old, why do I want to be going up and down stairs? I don’t.”
After whipping everyone up a nice lunch and wetting whistles with more delectable Oregon Trail IPA, Benton County Building Inspector Daryl Long showed up right on cue.
Wills and Long studied the engineer’s plans while Richards and his crew finished off the wall they had started that morning. By time Long was ready to leave, work had begun on a window frame that would ultimately join two sections of wall together.
On his way out, Long commented, “I’ve never seen rammed earth walls before. Wood frame, concrete walls, ICS, or stuff like that…Straw bale is becoming kind of in. It’s fascinating to watch the process.”
Standing on a concrete footer, Wills explains that when they start building the next section, there will be a large window facing south and capturing the verdant rolling Tangent hills. For now, the view is obstructed by the trusty trailer he and his wife have inhabited for the past 30 years.
“In 7 and 1/2 hours we have a wall, and who knows how many hundreds of years it’s going to be here, that’s the beautiful thing,” he said.
Much work remains to be done before Wills’ rammed earth house is complete, but this is very much the home stretch. Earth construction was an inspiration in Willis’ younger days, but now it is tangible – walls, footers, and door frames that can be touched. In the coming years a roof and flooring will be added and soon the ever-faithful trailer will be towed to the road and hung with a For Sale sign.
Until that time, Wills continue growing and selling Christmas trees all over the West Coast, shipping hops to home and microbrewers across the country, and brewing more tasty Oregon Trail treats.
If you want to learn more about the construction process, drop by Oregon Trail located in the back of Old World Deli and ask for Dave Wills, the rammed earth guy.
By Anthony Vitale