09 The Roof

The roof, being the biggest and most important construction element in the overall house design, needed to be carefully planned and constructed.  Simplicity was the guiding principle.  A symmetrical dual pitch roof with a gentle gradient of 20 to 25 degrees on each side was chosen as the basic form.  This eliminated unnecessary ridges and gullies that could become a potential point of leakage.  Spanning the entire width of the house, the roof would stretch over 120 feet from the North wing to the South wing with a single ridge dividing the roof in the middle.

With such a wide area being exposed to the sun and heat throughout the day, it was critical that the roof design effectively overcome the issue of solar gain.  Interestingly, the design drew its inspiration from Land Rover with its safari roof.

The safari roof was a device designed for the Series Type Land Rovers operating in the hot tropics.  A simple sheet of aluminium mounted on top of the vehicle with metal feet, sandwiched a layer of air for insulation, which, when heated sufficiently, dissipated the air along with the heat while drawing in cool air through a repetitive cycle.  More about this later.

In order to support the large expanse of roof, it was decided that large horizontal concrete beams would be constructed at regular intervals. The height of each was staggered to accommodate the pitch of the roof. I called this the "hurdle" design after the track and field sport.  This design was not new but borrowed the design method of the 1960s thereby adhering to the architectural style of the period.

Pic 1: The staggered "hurdle" beams that would eventually support the roof.

Pic 2: South wing extension viewed from the front.

Pic 3: A big challenge was to construct the concrete beam on top of the three main columns two storeys high.

Pic 4: Close-up of the concrete beam as it cures.  Note the circular cap that carries the columns' form all the way to the top.

Pic 5: Top view of the staggered "hurdle" beams and cross support beams.

Pic 6: A panoramic view of the roof beams from the south back corner of the house showing the systematic construction process from south to north.

Pic 7: The same view but from the opposite end of the house.