Roofing in the Western Cape

Wind from two directions

In July 2024 a run of winter storms led to a Level 8 disruptive-weather warning for Cape Town, Drakenstein and Stellenbosch. The City reported that strong winds had severely damaged formal and informal homes, and in Wynberg roofs were blown off. Then in summer the south-easter takes over. A report on CSIR wind research notes that high winds stop the Table Mountain Cableway on 70 to 80 days a year and have cost the Port of Cape Town an average of 1,200 operating hours a year.

For a homeowner, the lesson is that fixings matter as much as the covering. When you compare quotes, ask:

• How sheets will be fixed and how many fasteners per sheet, especially along edges and ridges where uplift is strongest.
• Whether loose or slipped tiles will be clipped or re-bedded, not just pushed back into place.
• How flashings against parapets and walls will be secured so wind-driven rain can't get behind them.

Salt air: distance from the sea sets the specification

A corrosion map of South Africa published in the South African Journal of Science found the country's most corrosive air is typically along the Western Cape coast, within 150 m of the ocean. Mild steel there corroded at up to about 460 µm a year near Melkbosstrand, which is in the extreme (CX) class. Between 150 m and 1 km from the sea the air was rated high to very high, and from 1 to 30 km inland moderate to high. The authors point to the onshore south-easter and the low fynbos and dunes, which do little to filter spray.

In practice, a sheeting roof within a kilometre or so of the sea needs a heavier metallic coating or a coastal-grade painted product, with fixings and flashings to match. Ask the roofer to name the coating class and show you the manufacturer's guidance on distance from the sea for your address.

Heritage permits for older Cape Town homes

Under section 34 of the National Heritage Resources Act, every structure older than 60 years, including parts of buildings, is protected. The City of Cape Town's heritage guide says a permit from Heritage Western Cape is required before the City can support alterations, so changing the roof of an older home may need two applications: the section 34 permit first, then building plans. If the property is in a Heritage Protection Overlay Zone such as Woodstock or Kalk Bay, work that changes its appearance also needs City consent.

You can check your property on the heritage layer of the City's EGIS map viewer, and the City's Environmental and Heritage Management office gives free advice before you apply. Do this before you settle on a new roof colour or profile.