Can a raft slab move or crack over time?

Some fine, stable hairline cracking is genuinely normal shrinkage behaviour in any concrete slab, raft slabs included — this isn’t a sign of failure, just an expected part of how concrete cures.

A properly designed raft slab, correctly matched to your soil conditions, shouldn’t experience significant structural movement — that’s precisely what the engineering design is meant to prevent by properly accounting for your site’s actual soil behaviour.

Cracks that widen over time, show a visible step, or appear alongside other signs like sticking doors warrant professional assessment — this is different from normal, stable cosmetic cracking and worth taking seriously.

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