Concrete Work in Mei Foo Sun Chuen

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.

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.

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.

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.

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.

Hairline shrinkage cracks are normal; that is what control joints are for — they give cracking a straight place to happen. Wide, uneven or lifting cracks signal a base, reinforcement or curing problem. If a new slab cracks outside its joints within months, call the contractor back.

Excavation and sub-base, formwork, reinforcement (mesh size or fibre dose), concrete grade and thickness, the finish (broom, trowel, exposed aggregate, stamped), control joints, curing method, and spoil removal. Any quote that just says 'supply and lay concrete' leaves too much undefined.

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.