Introduction
Concrete terrace walls are exposed to harsh conditions: poorly directed surface water, inadequate drainage, hydrostatic pressures, freeze-thaw cycles…
Over time, these factors can cause cracking, leaning, and safety risks for occupants.
Site Findings
The inspection revealed:
- Terrace T-1: light to moderate cracking, minimal leaning.
- Terrace T-2: moderate to severe cracking, noticeable tilt toward the terrace.
- Terrace T-3: severe cracking, displacement up to 4.5 in, significant structural risk.
👉 Surface slopes directed toward the walls and poor back drainage worsen the problem.
Analysis and Diagnosis
Main causes include:
- Inadequate drainage behind walls,
- Water accumulation and hydrostatic pressures,
- Freeze-thaw cycles,
- Insufficient reinforcement for cantilever resistance.
These mechanisms result in progressive deterioration, accelerated by harsh winters or heavy rain events.
Risk Assessment and Prioritization
- T-3: high priority – full replacement recommended.
- T-2: medium priority – monitoring and corrective measures required.
- T-1: low priority – monitor with minor repairs possible.
Technical Recommendations
For T-3 (critical wall)
- Demolish and rebuild reinforced concrete wall,
- Check/strengthen footing,
- Install new back drainage with clean stone and geotextile,
- Reinstall pavers and landscaping with proper slope.
For T-1 and T-2 (preventive measures)
- Verify and restore back drainage,
- Seal cracks on soil side to limit water entry,
- Adjust surface slopes,
- Monitor condition (photos, tilt measurements, spring inspection).
Conclusion
Retaining and terrace walls require close monitoring. Poor drainage combined with freeze-thaw cycles accelerates structural damage.
👷♂️ At Florcon, we provide detailed inspections, prioritize interventions, and propose solutions that meet CSA standards and safety requirements.
📞 Noticed cracking or leaning in your retaining walls? Contact Florcon today for a professional inspection.
Case of the Day – Inspection of Basement Terrace Walls in Montreal