Concrete placed against concrete that has already set does not fuse fully, leaving a plane of weakness that water follows. Cold joints occur at planned construction joints, wall-to-footing intersections and unplanned stops in a pour. Waterproofing details treat them with waterstops cast in, extra membrane reinforcement on the positive side, or injection after the fact.
Water's coming in right along the cold joint at the footing, the swelling strip must have been missed.
Also heard as
- pour joint
Related terms
Waterstop
A strip cast into concrete joints to block water from traveling along the joint plane.
Crack injection
Pumping polyurethane or epoxy into a leaking concrete crack through ports to seal it from the inside.
Positive side
The face of a wall or slab that touches the water source, where waterproofing works best.
Detail coat
An extra reinforced layer of membrane at corners, cracks, drains and penetrations before the main coat goes on.