What is a column kicker in construction?

A column kicker is a short concrete stub (typically 50–150 mm high) cast on top of a floor slab to mark the exact position and alignment of a column before the main column pour. It acts as a guide for fixing formwork accurately. However, the construction joint between the kicker and the main column is a cold joint — a known weak point for water ingress, particularly in basement and below-ground structures. We commonly waterproof column kickers using fillet seals or resin injection to prevent leaks tracking down the joint.