Foundations: original details
Original bungalows had suspended timber floors supported by piles set into the ground.
The perimeter was either piles with base boards covering the section between the base of the wall and the ground (Figure 1), or a continuous foundation wall of brick or concrete (Figure 2).
On sloping sites, ground clearance was often minimal with very limited underfloor access or ventilation at the higher ground level. Needless to say, this often had detrimental consequences for the subfloor construction.
Precast concrete piles also became available during the 1920s, although they were not extensively used until late in that decade.
Piles were typically arranged in lines or rows, at centres to support bearers spaced between 4’6–6’0” (1.350–1800 mm). The lines of piles were generally between 4’8–6’6” (1400–2000 mm) apart.
The perimeter walls of weatherboard-clad bungalows were often supported on bearers and piles, in which case the area below floor level was typically enclosed by horizontal or vertical base boards.
If horizontal base boards were used, the transition between the weatherboards and baseboards was often defined by a timber moulding (Figure 4). Alternatively vertical boarding, often splayed to form a ‘skirt’, was used.
Another option seen occasionally are bevel-back weatherboards taken to ground level and formed as a bell cast or outward curve (Figure 5).
Although reinforcing was used in concrete construction at the time, it is uncertain whether foundations walls were commonly reinforced. It is likely that some reinforcement would have been used but probably not to current Building Code requirements.
A timber plate was cast into the top of the concrete wall to provide fixing for floor joists. Bearers were supported in recesses cast into the foundation wall.
A damp-proof membrane was not usually installed between timber and concrete. In Figure 6, the bearer is supported on a cast-in recess in the foundation wall and there is no evidence of a damp-proof membrane between the timber and the concrete.
In Figure 7, the fully-enclosed subfloor spaces created by a continuous, concrete perimeter foundation wall require ventilation and although ventilation grilles were generally included, they tended to be insufficient in number to provide adequate subfloor ventilation).
The concrete foundation wall was commonly used on hillside sites (such as in Wellington). Sometimes the foundation wall was stepped and extended in height by jack stud timber framing for the rest of the foundation wall.
The basement spaces thus created provided useful storage space and in many situations these spaces have subsequently been converted to habitable spaces, although not always successfully – unless they are well waterproofed, they are prone to be damp.
In situ concrete, continuous foundation walls were finished on the exterior face with a stucco plaster finish.