Select and place waterstops at below-grade concrete construction and expansion joints

Steps

1. Use PVC waterstops (heat-welded at joints/intersections for a continuous diaphragm) as the industry-standard flexible type for below-grade construction and cold joints — ACI 350 (Code Requirements for Environmental Engineering Concrete Structures) is a commonly cited acceptance reference; confirm the current edition on concrete.org before citing a specific provision.
2. Use hydrophilic waterstops (rubber or bentonite-enhanced strips that swell on contact with water) at non-moving construction (cold) joints where they don't need to be secured/centered ahead of the pour the way ribbon PVC waterstops do.
3. Match waterstop type to joint type: expansion/movement joints generally need a flexible center-bulb elastomeric waterstop designed to accommodate movement; construction joints between sequential pours are commonly served by PVC ribbon or hydrophilic strip waterstops.
4. Maintain continuity around the entire joint, including corners and intersections, with proper factory- or field-welded/spliced connections at direction changes — an interrupted or poorly spliced corner is a common leak path.
5. Ensure proper concrete consolidation (vibration) around ribbed PVC waterstops during placement — voids/honeycombing against the waterstop from inadequate consolidation is a common as-built defect.