Homeadow Song Farm
Cob/Radiant Floor

	Gray Rd is a curious anachronism, with an almost rural ambiance hidden in the midst of an industrial center of the city. We arrived -- my daughter and I -- in mid-afternoon for an opportunity to work on the cob/radiant floor that Homeadow Song Farm is installing in their music studio. The farm is the project of a group of bio-dynamic farmers and artists, who apply Rudolf Steiner's processes, share their interests with homeschoolers in the area, and generally create a world of their own that reminded us of our days living in the eco-village of DeerRock in the BlueRidge Mountains of VA. To see the effect of the entrance, with the main house, gazebo, parking area and rustic play area, you can expand the panorama we stitched together above. Yet it's futuristic too, compared to just about any other sight in that area, or basically any other area of Cincinnati. Check out the rooflines, count solar collectors and even an earth-covered roof, before we've even gone very far.
We headed on down the driveway that curved into the leafy distance, and came to the construction site, easily recognizable by the cob material piles. But across the driveway was a solar heated outbuilding, and beyond that was the rumored cob oven beneath a picnic shelter and adjacent to what looked like a fire circle where folks gathered. Within moments we were greeted by a few of the HMSF residents, returning from chores of various sorts. Our cob-workday guide -- Peter -- was back in the garage and joined us shortly.
The advantage of living on a farm is the opportunity presented by outbuildings. The one across the drive was solar -heated. Their puppet barn had PV-powered stage lighting with plans for a larger system. The horse barn would inherit the original PVs. The music studio is the building with the window wall (facing south) and the clerestory windows above when you expand the scene to see the panorama. You'll also get to see the earth-covered roof, their first. They have plans for another experiment like that.	Above is the cob oven for baking bread, and the gathering circle. To piece the scene together, the link to the panorama is behind the photo above.

They had done the usual soil tests to analyse the content of the soil, including the jar test, a drop test and rolling a rope. There's a very good appendix in David Easton's book on rammed earth that details a whole series of soil tests that are doable. The tests confirmed that the soil was within the ranges needed for cob, so they proceeded to experiment with some of the techniques described by various authors.	As soon as Peter arrived we settled down to a tour of the cob progress. They had already excavated the floor and the soil beneath from the studio, using a rented mini backhoe, and heaped the soil just outside, in front of the window wall. The foundation went down below the frost line and they had dug down a bit more than a foot, laid in a rock level that was several inches deep, topped by a few inches of crushed lime. Next came a vapor barrier and the insulation. The walls also had a layer of pink insulation board, the better to keep the eventual radiant heating inside. There were buckets of soil accumulating in one area. A small room to the side was the staging area for radiant coils as well as the safekeeping area for some of the testing they'd done.
	The books on cob are not very consistent or specific on mixing procedures and methods of application. Some advocate simply laying the soil in and tamping but that didn't work with this soil. Rather beach like, instead of what was wanted in a music studio.
	So Peter and crew went to work, experimenting with mixing procedures, built a little form for doing tile samples of their results and eventually they arrived at a viable mix and method, which they confirmed with a full scale test in another side of the room. Their experimenting is not quite done, as they begin looking at finishes, sealers and such. They're also interested in observing the curing process for their cob over a little longer time frame. Meanwhile they accumulate materials and tend to other work.

The wall areas for the radiant floor manifolds and other periphernalia were open so you could see some of the piping coming into the room. To see one of the manifold walls with visible copper piping waiting for the next stage, the link is behind the photo below of the interior of the studio, facing the window wall. The good test floor area is in the corner near the ladder. It is curing very slowly.

With that perspective, we went back outside and settled down to the task of preparing the soil for cobbing, namely removing any stones over about a 1/4inch and sifting the rest to a fine consistency. To keep the soil dry enough for sifting they keep the pile covered with a plastic tarp that's anchored with scrap lumber. Peter had experimented with catching the sifted soil in a wheelbarrow and wheeling it indoors but the sills and step (with ramps set up) was still more arduous than the simple bucket loading and short route through the windows. We think he might consider our other suggestion of a sloping chute below the sifters that funneled the cob material directly into buckets.	They built sifting trays using hardware mesh bottoms and set them comfortably at a suitable working height. The fine cobbing soil accumulated in heaps below, to be later loaded into 5gallon buckets and passed into the studio through the windows behind.
Then it was a matter of massaging the soil to push as much clay/silt through the mesh as we could. Peter and our hostess provided us with work gloves and sunhats, but I was feeling pretty confident and alert and I prefer bare hands because there wasn't much glass.	The surface accessible soil was not compacted and was not difficult to handle. Peter may need to use a tiller on the lower layers to keep the shovel work and sifting running smoothly.
Each time that we sifted through a batch of about 3-4 shovels full of soil til all that was left in the sifter was the larger rocks, we tilted the tray so the stones slid to the near end of the tray, reducing the stress of hefting the tray and emptying it into the waiting wheel barrow.	The weather was gorgeous and it was easy to carry on great conversation with no engine noises to disturb the flow. And with the flower beds right next to our work area, we had occasional visitors of the feathered type, a chilean breed of hen simply going about their business among the foliage.
	We hope to return when Peter and Randy are ready to do the radiant floors. I'm told we've barely scratched the surface on projects and fun.


More to explore.