Isolation Joint

1. Introduction

Isolation joints separate two dissimilar materials or structural elements (e.g., column–slab, wall–floor) to prevent stress transfer due to differential movement.

These joints are critical for avoiding cracks and leakage at structural interfaces.

2. Typical Failures

• Missing compressible filler board.
• No edge sealant leading to seepage.
• Debonding between concrete and sealant.
• Inadequate gap width or poor compaction.

3. System Requirements

• Provide physical separation with compressible filler.
• Apply waterproof edge sealant to prevent ingress.
• Maintain flexibility and continuity with adjacent systems.

4. Recommended Systems

5. Methodology

1. Install compressible filler before casting concrete.
2. Trim flush after de-shuttering.
3. Apply primer and PU sealant over top edge.
4. Provide watertight continuity with waterproofing system.

6. Performance Parameters

7. QA/QC Checklist

• ☑ Correct filler type and thickness
• ☑ Flush edge finish
• ☑ Sealant cured
• ☑ No visible gaps or discontinuities

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