Can a house slab be built during a heatwave?

Yes, but the process changes — extreme heat speeds up how fast concrete sets, so contractors adjust the pour timing (often starting earlier or working into the evening), use retarding admixtures, and cure the slab more aggressively to stop it drying out and cracking.

Genuinely hot days (35°C-plus) are treated as a real risk factor, not ignored — your contractor should flag a heatwave pour in advance and explain what they’re changing, rather than pouring exactly as they would on a mild day.

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