19 Rockridge

19 Rockridge is a private house on a ridge in Johannesburg, looking north over the treed suburbs. The architecture is thin, low-pitched roof planes carried on steel and timber over glass, brick and stone, with deep overhangs. There is no loft and no ceiling void: the roof plane is the ceiling plane, inside and out.

Technopol supplied the roof and part of the external skin. The roof is LiteSpan 990 Standing Seam — Chromadek steel skins factory-bonded to a fire-retardant FRCel EPS core, 990 mm cover, white underside. The product spec gives the fixing as a concealed 1.2 mm galvanised clip at every support, two screws per clip. No clip is visible in any photograph of this job; what the photographs show is the consequence — no fastener head in the weather face, and nothing in the field of the roof but the seams. The upper walls are clad in LiteClad ClipClad, the 270 mm concealed-fix profile in 0.5 mm pre-painted steel, run vertically.

The demanding part of this job is that the panel is seen from both sides. One photograph here is a crew working on the laid panel outside, harnessed, at the far edge of the roof; another is the same panel type overhead, as the finished ceiling of the double-volume living room. There is no ceiling board under it: the panel joints are the ceiling joints, and the factory skin is the finish. There is no separate insulation over it either — the insulation is the core — but that is the composite build-up in the spec table, not something these photographs show, because no frame in this album looks down on a laid panel. That is what a composite panel has to earn: a soffit good enough to live under.

It also had to be thin and shallow. In the photograph at the top of this page the roof reads as a floating plane, a deep eaves overhang with no fascia bulk. The datasheet takes the Standing Seam profile down to 3° pitch, and because the clip is concealed there is no fastener line to detail around at the eaves.

The cladding is fixed the same way. Per the datasheet the wafer screw goes through the lip and the next sheet laps over it; in the photograph where the run stops, the finished stretch carries no fastener head on its face and the horizontal rails it lands on are still open on the sheathing. It meets raw brick and stone piers directly, without a cover trim.