Block, concrete or timber? Choosing materials in Barbados

Concrete block: the default, and usually right

Why it wins here: it does not burn, termites have no interest in it, it stands up to hurricane wind and flying debris, it has thermal mass that evens out the day's heat, and the materials and the skills are available on the island.

What it needs to be done well: reinforced concrete columns and ring beams tying it together, correctly lapped steel, proper mortar, and render detailed so water does not sit in it. Blockwork on its own, without the concrete frame around it, has very little to offer against lateral and uplift loads.

Reinforced concrete: superb, until the steel rusts

Reinforced concrete does the structural heavy lifting: footings, columns, beams, slabs and concrete roofs. It is strong, durable and excellent in a hurricane.

It has exactly one serious enemy in this climate: chloride attack on the reinforcement. Salt-laden air near the coast reaches the steel through porous concrete or insufficient cover; the steel corrodes, expands, and blows the concrete off. You see it as rust stains and spalling.

The defences are unglamorous and non-negotiable: adequate cover to the steel, held with proper spacers; a dense, well-compacted mix that was not watered down to make it easier to place; and curing — keeping it damp instead of letting the sun bake the water out in a day. Get those three right and the structure outlives everyone involved.

Timber: where it earns its place

Good for: roof structures, joinery, decking, shutters, internal fit-out, and traditional construction where it is detailed the way it was designed to be.

The two enemies: termites and moisture. Timber needs to be treated, kept clear of the ground, ventilated so it dries, and detailed so water cannot sit against it or track into the end grain. A well-detailed timber roof performs excellently in a hurricane. A poorly fixed one is the classic failure.

Hardwoods and properly treated timber cost more and last dramatically longer. Cheap softwood outside is a false economy measured in seasons.

Steel: strong, and it rusts

Structural steel, roof sheeting, railings, gates and fixings. All of them corrode near the sea, and faster than people from temperate climates expect. Use galvanised or stainless where it matters, keep coatings maintained, and never mix incompatible metals in contact — that accelerates corrosion all by itself.

Fixings deserve particular attention. A roof held down by fasteners that have rusted through is a roof held down by nothing, and you cannot see it from the ground.

Roof coverings

• Metal sheet — light, fast, economical, and entirely dependent on the quality and spacing of its fixings. Choose the coating for a marine environment.
• Concrete or clay tiles — heavier, quieter, good in wind when fixed properly, and every one of them must be mechanically fixed near the coast.
• Concrete roof slab — the most resistant to uplift, the most expensive, and it must be waterproofed and maintained.
• Shingles — attractive, and demanding on maintenance in this climate.

What the climate does to everything

The honest summary

Block and reinforced concrete for the structure, well-detailed timber where timber earns its place, corrosion-resistant fixings everywhere, and money spent on the parts you cannot see rather than the parts you can. Nothing about that is fashionable. It is simply what lasts here.