Building at the Kenyan coast: materials that last
Salt air, humidity, termites and heat: how to choose materials and details for a home in Diani, Ukunda, Kilifi or Mombasa that will last.
By Redbay Group ·
The coast is hard on buildings
Salt in the air, high humidity, strong sun and termites all work against a building at the coast. Materials that last for decades inland can rust, rot or stain within a few years near the sea. Planning for this from the start costs far less than repairs later.
Steel and metalwork
Salt air makes ordinary steel rust quickly. For railings, balustrades and fixings, use marine-grade stainless steel or properly galvanised and painted steel. Check the grade, not just the shine: cheaper stainless steel can still stain near the sea.
Inside concrete, the reinforcement needs enough concrete cover and a good mix so salt cannot reach it.
Clean sand and good concrete
Sand used for concrete and plaster must be clean. Unwashed sea sand carries salt that attacks reinforcement and causes damp patches on walls. Ask where the sand comes from.
Coral stone
Coral stone is a traditional coastal material. It keeps houses cool and gives a warm finish when used as cladding. It is porous, so it should be sealed and kept away from standing water at the base of walls.
Timber and termites
Termites are common at the coast. Use treated hardwood for pergolas, trusses and doors, and treat cut ends on site. Treating the soil under the foundations before the slab is cast is also worth doing.
Design for heat and air
The best coastal homes stay cool without relying only on air conditioning:
- Cross ventilation through the main rooms
- Deep overhangs, balconies and pergolas that shade walls and windows
- Pale roof and wall finishes that reflect heat
- Breathable paints that let damp walls dry out
- Aluminium windows and doors, which do not rot or swell