Everything Here Is a Roof Over Something Else
The defining feature of a Clifton building is that it is stepped down a cliff, and the consequence is that horizontal surfaces are almost never simply outdoor space.
A deck on one level is the ceiling of the level below. A terrace is a roof. A pool surround sits over a bedroom. A staircase landing covers a store room. In a conventional house, a leaking patio is a nuisance. In a Clifton bungalow, it is water in the room underneath.
Timber decks are the specific problem. A great many Clifton properties have timber decking over living space, and the waterproofing on those has to be beneath the deck structure, not on the boards. Deck boards are a wearing surface with gaps in them by design. The membrane below is what keeps water out, and every joist fixing and post base that penetrates it is a leak point that needs detailing.
What we find repeatedly is decking laid over a membrane that was never designed to be walked on or built over, or fixed straight through a membrane with no detail at all. It works for a few years and then the room below starts staining.
Falls under a deck matter as much as falls on a roof. Water that gets through the boards, which it will, has to reach a drainage point. A flat membrane under a deck with no fall is a tray holding water permanently.
Access for repair is the second problem. Investigating a leak under a timber deck usually means lifting boards, which is disruptive and which nobody wants to hear. Doing it properly the first time is considerably cheaper than doing it twice.
Exposure on Every Side
Clifton buildings are exposed in a way that few others are, because they stand out on a slope with little shelter from anything.
Winter north-westerly fronts come in off the Atlantic at 50 to 65kph, unobstructed. Rain arrives horizontally and hits elevations from the side rather than falling on the roof. Glazed junctions, sliding door tracks and frame-to-wall interfaces take the loading.
Direct salt spray. Proximity to the water at Clifton 4th and the surrounding beaches means salt on everything, continuously. Metal fixings, balustrade bases and exposed steel corrode fast, and concrete takes chloride the same way Sea Point does.
Full sun on west-facing elevations, degrading sealants and exposed coatings quickly.
Wind uplift. On an exposed cliffside, wind does not simply push, it lifts. Membrane edges, flashings, sheet edges and anything not mechanically secured is subject to uplift forces that a sheltered building never sees. Perimeter fixing and edge detailing matter here more than almost anywhere in Cape Town.
Reflected light and heat off the sea and off pale surfaces adds to the UV load.
Working on a Terraced Site
Practical realities that affect every job here, and that we would rather set out honestly than surprise you with.
Material handling. Where there is no vehicle access, materials come down or up by hand, by stair, or occasionally by other means. That is labour, and it goes in the quote as its own line rather than being buried.
Staging and storage. There is often nowhere to put materials, which means smaller deliveries more often, and a longer programme than the same job would take on a flat site.
Waste removal. Everything that comes off the building has to go back up the same way it came down. Strip-off jobs are disproportionately more work here.
Neighbouring properties. Buildings sit close together on stepped terraces, and access frequently requires cooperation. We sort that out in advance rather than on the day.
Weather windows. An exposed cliffside site is unworkable in high wind for safety reasons, quite apart from the material requirements. That affects scheduling and we build it into the programme.