Building a whole tree timber frame house is an exercise in patience.
We have been working with these timbers for almost a year now — selecting them from our 44 acres last summer, peeling and felling them, then working out a master plan for how their individual branching natures could fit together trunk-to-branch in homage to the forest they came from.
This winter and spring we worked alongside the construction crew as the surface of each timber was shaped with draw knives and angle grinders, sanded smooth, and then painted or stained. In the process I have come to know some of the more distinctive timbers very intimately, working an orbital sander over every rise and fall along their sinuous length.
The first step after the concrete foundation walls were poured was to frame out a conventional, 2×8 milled lumber wall on top of the slip form masonry wall that forms the walkout portion of the basement. (The milled lumber came from the Ridgeway lumber yard less than two miles up the road.) It was a powerful sensation to actually feel the enclosure of that space. We invited some friends over the Friday before last and hosted our first dinner – a picnic within four walls and under the vast and darkening sky.
Over the last two weeks, the main floor has taken shape above that space.
The first whole tree that was put in place was the main beam, a massive oak tree trunk that spans the full 28 foot length of the basement. Getting it situated was the work of many meticulous hours. The biggest single beam in the structure, it was carted up to the house on the fork lift and balanced carefully on the concrete foundation walls.
There was only a few inches of leeway on either end of the beam. If one end had started rolling faster than the other, it would have rolled at an angle off the wall and thundered onto the basement floor. Moving it into place was done very slowly, using cant hooks and constant feedback between two crew members on each end.
Unfortunately communication was confounded when the well digging trucks arrived in the middle of the process. The roar of the drilling rig drowned out even shouting. Sign language and a lot of running back and forth finally got the beam positioned and lowered into its pocket.
Between the two ends of the beam, along its entire 28 foot span, the only support is a stout, branching elm trunk placed right in the middle, sitting on a reinforced concrete footing that goes down to stone and packed earth, just a few feet above the bedrock below.
It’s not necessary for the joists to be exactly level. After the metal decking is attached to the tops of the joists, the floor is covered with concrete, and that surface was leveled.
What we will see between the joists and rafters from below is a surface formed of taught hemp fabric that is stapled to the tops of the beams. Above them several layers of insulation were spread out and finally a layer of metal topped them to form the base for the concrete pour.
Read about the saga of our concrete pour in my post …..
At long last, the stage was set for the assembly of the whole tree timber frame that will form Underhill House’s contours and create its tone. This week that process began.
Timber framing is always part art and part engineering, and that is what forms such undeniably compelling structures. Whole tree timber framing takes both the art and the engineering to a higher level.
Fitting together timbers that have not been milled into uniformity for the convenience of the builder takes imagination and finesse. It’s been a joy to watch the dance involved in selecting and fitting these branching members together.
Underhill will have three bents: the highest one on the south wall to let in light and solar heat, the shortest one on the north wall to hunker down against the winter winds, and one in the middle bridging between them.
First to take the stage was the middle bent. The central beam is formed by joining two massive trees with bolts and a steel plate. Its natural bends will create the curve of the roof.
The north bent was the next to be fit together.
The final, tallest, south bent will be assembled on the ground in front of the house because there is not enough room for all three to lay out on the concrete floor.
Next week a crane is scheduled to fly them all into place. I can hardly wait to see their clear, white forms etched against the blue, blue sky!
I am so happy to be building a home of wood in a way that honors the shape and provenance of the wood and benefits from all the strength that each tree created year by year, responding to the forces around it, bending and branching to reach the light and withstand the wind.
Preparing and fitting together these whole tree timbers has taken more time than putting up a frame of milled lumber, but that time has meant employment in our community for some dedicated and skilled sustainable builders. It’s also the greenest and most beautiful way I know of to build our house.