Concrete Work in Pok Fu Lam

Common rules of thumb: 75-100mm (3-4") for paths and patios, 100-125mm (4-5") for driveways and garage floors, more for heavy vehicles — always over a compacted sub-base with mesh or fibre reinforcement. Thin slabs on soft ground crack no matter how good the finish looks.

Strongly. Frost can ruin an uncured pour, extreme heat causes plastic shrinkage cracking, and rain marks fresh surfaces. Good contractors watch forecasts and will delay a pour; be suspicious of anyone happy to pour into bad weather to keep the schedule.

Broom (non-slip, standard outdoors), steel trowel (smooth, indoor), exposed aggregate, stamped/patterned, coloured and polished. Decorative finishes can add 30-100% to the base rate but replace the cost of a separate surface like pavers or tiles.

Surface spalling, small cracks and pitting can be patched, resurfaced with an overlay, or ground back. Slabs that have sunk can sometimes be lifted with foam or grout injection ('slabjacking') for far less than replacement. Structural failure or widespread base movement means replacement.

You can usually walk on it after 24-48 hours, drive on it after about 7 days, and it reaches design strength at 28 days. Curing (keeping it damp, protecting from frost or extreme heat) in the first week matters more for durability than almost anything else.

Concrete is priced by area and thickness for slabs (per m² or sq ft), by volume for supply (per cubic metre/yard), and by the job for repairs. The concrete itself is often less than half the bill — formwork, reinforcement, sub-base preparation, finishing and access drive the labour cost.

Decades-old reinforced concrete plus humid, salty air corrodes rebar, which expands and pops the cover concrete. Proper repair means breaking out to sound concrete, treating the steel, and rebuilding with repair mortar — patching over it just delays the next fall of concrete.