This revolution has its origins even before my Revolution in Roofing click here to read article. It goes back to the very beginning of mankind and our Kalinago ancestors were practicing it long before Columbus.
In a nutshell, it is all about building circular structures and deflecting wind force rather than fighting against it. Have you ever seen a square sided tree or a flat fronted racing car? No, you haven’t. But we continue to build slab-sided houses!
A circular house is many times stronger than its square-cut neighbour and, for the same amount of perimeter wall, it contains almost 20% more floor space. It also lends itself to creative possibilities in terms of layout and interior design.
The floor plan and cross section that illustrates this commentary is for a house 50 feet in diameter. Surrounding the central living room are three bedrooms, two bathrooms, entrance hall, kitchen, store room and study. A diameter of 30 feet can accommodate a single bedroom, bathroom, study and an open plan living room and kitchen. For “study” you can read “work room”. In years to come the internet will enable many desk jobs to be done from the home environment.
The perimeter wall is topped by reinforced concrete beam. At their lower end, rafters are bolted onto steel lugs that are cast into the beam. At their upper end the rafters are bolted to lugs welded to the steel frame of the cupola and radiate like spokes of a wheel. Alternate rafters are half the length of a full rafter and terminate on cross beams. The purlins can be bent in situ to follow the curve of the roof. All of the roof’s lateral force is absorbed by the perimeter beam. The walls are only subjected to a helpful compressive force. The internal walls are none structural.
All window openings are protected by shutters and there are no overhanging eaves to catch the wind. Custom molded fiberglass guttering extends under the bottom row of tiles and its vertical face serves as fascia for the ends of the rafters. Hence, the guttering is an integral part of the roof.
The steel framed cupola is an essential design feature. The toughened glass lantern allows day light to stream into the central living room and the louvres provide ventilation.
There is no way that corrugated sheets of galvanized can conform to the roof’s conical form, but clay tiles or shingles can.
Incidentally, the semicircular 1st and 2nd World War Nissen Huts used corrugated galvanized to its best structural advantage. The Nissen Hut concept is still relevant in terms of emergency re-housing. The standard hut could be erected by six men in four hours.
At this point let me thank DNO readers that responded to my clay tile commentary. The main concerns related to breakage and cost. Due to flat clay tiles having a generous overlap and closely spaced purlins, when laid they are amazingly resilient to breakage. In terms of cost, the roof is only one component of the building and furnishing investment. And if you go up a level, the same roof covers both upstairs and downstairs.
I am told that bricks were once made out of local clay at Canefield and possibly clay roof tiles at Portsmouth. Bricks, floor tiles and roof tiles all share the same clay and method of firing. If these industries were revived, the walls, floor and roof of my circular house could be manufactured locally.
Illustration shows the author’s plan for a circular house.