Monolithic pour
A monolithic pour casts a slab and its beams together in one continuous pour so they act as one element, avoiding the cold joint that would weaken a raft slab.
Ask Chalkline about this →A monolithic pour is casting a concrete slab and its edge and internal beams together in one continuous pour, so the whole thing sets as a single element. It is how a stiffened raft slab is built: the perimeter beams, the internal beams, and the floor panel are poured at once, not in stages, so there is no joint between the beams and the slab they stiffen.
The point of pouring it monolithically is to avoid a cold joint. A cold joint forms where fresh concrete is placed against concrete that has already started to set; it is a weak plane that can crack, leak, or fail in shear. In a raft slab the beams do the structural work of resisting ground movement, and they only do it if they act as one piece with the panel. Pour the beams one day and the slab the next and you have a cold joint exactly where the load is, which defeats the design. So a residential slab is normally poured in a single continuous operation, with the concrete kept moving so each load knits into the last before it sets.
Plan the pour as one operation: enough concrete trucks and pump capacity to keep going without a stall, the reo and void formers set and inspected at the hold point, and a plan B if a truck is late, because a stall in the middle of a slab pour creates exactly the cold joint you were trying to avoid. Where a construction joint is genuinely unavoidable on a large slab, it is a designed joint with continuity steel, not an accidental cold joint. See raft footings.
Also known as: Single pour, one-pour slab, monolithic slab.
Category: Concrete / Slabs.
Related
See also
References
- AS 2870:2011 Residential slabs and footings, Standards Australia (verified 2026-05-10)
- ABCB NCC 2022 Housing Provisions Part 4.2 Footings and slabs (verified 2026-05-10)
Last updated: 2026-05-30. Verified: 2026-05-10. Quarterly review for currency.