Does a raft slab need bored piers as well?

Not always — a standard raft slab on genuinely suitable, stable soil can perform adequately on its own. Bored piers are added when your site’s specific conditions call for them, such as variable soil across the site or where deeper, more stable bearing is needed at specific points.

This is a genuine engineering decision based on your soil report’s findings, not a standard add-on applied to every raft slab regardless of need — many raft slabs are built without any piers at all.

Where piers are recommended, it’s because your engineer has identified a specific reason your site needs them — worth asking directly what that reason is if you’d like to understand your specific design better.

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