In NYC, facade defects and cracks rarely “appear overnight.” In most cases, they follow a trend: micro-movements → crack opening → accelerated material degradation → a costly shift into emergency response mode. With increasing façade compliance pressure (FISP / Local Law 11, shorter shed timelines and stricter renewals), owners and engineers increasingly need measurable, repeatable evidence of deterioration dynamics, not one-off visual observations.
1) Engineering framing: a crack is a symptom-its regime matters
The core engineering question is whether the crack is stable or active:
- Stable crack: seasonal opening/closing without an upward baseline drift.
- Active crack: sustained increase in crack width/length and/or acceleration of growth rate, often coupled with deformations (settlement/tilt/deflection) or moisture/corrosion acting as degradation “accelerators.”
Conclusion: crack monitoring is only technically meaningful when paired with drivers and amplifiers: settlement/differential, tilt/deflection, moisture/intrusion/groundwater, corrosion indicators.
2) How infrascan.ai executes “in the field”: zoning → sensors → alert logic
Step A — Zone-based monitoring. The building is divided into control zones (corners/interfaces, above openings, expansion joints, basement walls, leak-prone areas). For each zone, thresholds are defined not only by value, but also by rate of change (rate), plus rules for “which signal combinations constitute an engineering event.”
Step B — Typical sensor stack (minimum viable set) and dashboard parameters
- Crackmeter (crack opening): GEOKON Model 4420 VW Crackmeter / or a wireless Senceive Crack Sensor → Crack width (mm), Crack growth rate, Crack activity index
- Tiltmeter (geometry/verticality): Jewell Instruments Model 801 “Tuff Tilt” (incl. 4–20 mA configurations) / or wireless Senceive Tilt → Wall tilt X/Y, Tilt rate, Geometry anomaly flag
- RH/T probe (microclimate/moisture): Vaisala HMP110 → Basement RH (%), Temperature (°C) → derived Moisture risk
- Water intrusion (leak/water event): Monnit Water Detect / Water Rope → Water intrusion event (0/1) + duration/counter → event timeline + annotations on crack/tilt plots
- Groundwater level (relevant for basements/post-flood): In-Situ Level TROLL 500 → Groundwater level / pressure + correlations with moisture/intrusion and crack activity
- Corrosion / rebar activity (where applicable): CorroWatch multi-probe (embedded monitoring) and/or Giatec iCOR (periodic NDT) → Half-cell potential (mV), Corrosion rate/index, Resistivity → Corrosion risk
3) What this looks like in live SHM dashboards (engineering logic, not just plots)
infrascan.ai operates three layers:
- Time series: crack width, tilt, RH, intrusion events, groundwater, corrosion metrics
- Derived signals: growth rate, tilt rate, smoothed trends, activity/risk indices
- Statuses: watch / warn / critical + event log
Key principle: “Active Crack” is triggered by a combination, not a single sensor: rising Crack growth rate plus confirmation by at least one mechanism (tilt/deflection, differential settlement/rate, moisture/intrusion, corrosion indicators). This makes alerts technically reproducible and actionable for engineering decisions.
4) Verification: when Drone/LiDAR is introduced
Drone/LiDAR is initiated by trigger, not on a content schedule: georeferenced defect capture, 3D geometry of the affected zone (interfaces/parapets/above openings), and-when relevant-thermal/visual confirmation of moisture pathways correlated with crack progression.
5) Demo access
In the infrascan.ai client portal, dashboard titles on the website are configured as links: clicking a dashboard name opens the corresponding live demo SHM dashboard.
