Initially published on Traditional Building Magazine online February, 4th 2019
Last autumn I was passing through the Shenandoah Valley of Virginia and decided to drop in on a good friend of mine, traditional timber framer Jordan Finch. Jordan and I had taught together at the American College of the Building Arts in Charleston, SC. When I arrived he was busy hand chiseling and fitting the mortise and tenon timber joints for a project with fellow timber framer Robert Laporte. Robert and his wife Paula have a company EcoNest that specialises in design build of homes, traditionally timber framed with light clay straw infill, that are typically lime plastered inside and out. I gave them a hand for a day and ultimately Robert recommended me to the homeowners for the plasterwork. The whole process was fascinating and I'll endeavour to share from this experience the type of home that is today possible by the combination of highly skilled means and methods of traditional craft with the truly sustainable ethic of a contemporary natural building approach.
Timber Framing and Light Clay Straw
|Robert Laporte has a young apprentice|
|Light Clay Straw Infill|
Interior Lime Rendering and Clay Finish
For the interior perimeter walls we installed lath followed by removable wooden grounds that we used for scratched render followed by applying and leveling the brown coat with rods and compressing with wooden floats the following day. The plaster mix was a combination of two local sands, hemp fibres for tensile strength and Lafarge Natural Hydraulic Lime as the binder. The first week all of the preparation and scratch render went up and with the hydraulic properties of the lime setting in we were in good shape for the next float coat and clean up by week two. Lime plasters were the perfect choice as they are exceedingly durable and share the moisture permeability of the light clay straw substrate.
Whereas all of the interior perimeter walls received lime plaster, the inner walls had been framed and received drywall. For the finish we applied American Clay plaster as a nominal 1/8" veneer over both surfaces, the lime plaster and the drywall, for a unified finish. Lime and clay are both traditional materials, practically inexhaustible resources that are completely non-toxic. The means and methods of application go back to the dawn of civilisation: hawk, trowel, rods and floats. The work is physical but not brutal on the body. Essentially plastering makes for good exercise!
Exterior Lime Stucco
Hand Carved Islamic Dome
Included in our commission was the design, construction and installation of an enriched plaster dome of Islamic geometric design for the "mihrab" or private chapel of the owners who presented me with a rendering of an hexadecagram, a 16-sided star polygon as a point of departure for the design. The first challenge was to determine the surface to receive the design, to research what kind of curvature for the dome was possible given the architectural constraints of the room height, the potentially obstructing rafters above and even the thickness of the dome itself. We managed to squeeze out the most curvature possible with a profile generated by a three-centred arch, an approximate ellipse.
Translating the interlaced pattern from a scaled two dimensional drawing to the three dimensional surface of the dome was another important step involving more geometry. The dome was to be cast; this meant that the "void" had to be first extruded in plaster. Onto that inverted surface the pattern was carefully and methodically transferred, physically inscribed utilising several methods to verify its precision. This accomplished, the casting of the dome in a relatively thin shell of plaster could commence.
Islamic geometry participates in a universal tradition of sacred geometry. Principles of the sacred feminine in harmonious relation with the sacred masculine were intrinsic characteristics of the tessellated dome that I sought to augment. For example, the "void" of the dome can point to the vault of heaven but has a perhaps stronger correlation with the universal "womb", the unseen and unknown mystery out of which all emerges. Rather than being considered empty or being nothing, the void symbolises that which is as of yet undifferentiated...potential itself. The gentleness and ethereal nature of the void is contrasted with the rigourous order, the imposed and revealed pattern of the tessellation.
Contributed by Patrick Webb