Home > Geotechnical Regions > New York Coastal & Long Island
Geotechnical Soil Profile

New York Coastal & Long Island Foundation Underpinning

Addressing Coastal Glacial Outwash Sands, Saturated Silts, & Urban Marine Fill with deep structural helical piles.

Primary Soil Classification Coastal Glacial Outwash Sands, Saturated Silts, & Urban Marine Fill
Plasticity Index (PI) Low (PI 0–15) / Highly Saturated
Seasonal Active Depth Zone Tidal Inundation Zone + 36-inch frost line
Load Bearing Refusal Standard Site-specific; advanced through coastal saturated sands/silts to verified torque resistance based on flood uplift loads

Geotechnical Foundation Hazard

Coastal storm surge scour, high tidal water tables, and saturated unconsolidated sands. Severe post-Superstorm Sandy requirements require raising existing homes above FEMA Base Flood Elevation (BFE), requiring deep pilings capable of resisting wave uplift and lateral wind loads.

Engineering Solution & Underpinning Physics

On Long Island's South Shore and across NYC coastal estuaries, high groundwater (often within 3–5 feet of the surface) renders concrete footings ineffective. Helical piers offer immediate installation in saturated sands without dewatering, and generate significant tension capacity to anchor elevated structures against coastal wind shear and storm surge buoyancy. Note: Depth to competent outwash sand varies with distance from coastal barrier inlets.

Local Building Codes & PE Stamped Requirements

Regulatory Compliance Notice: New York City Building Code (Appendix G Flood-Resistant Construction) and Long Island municipal building departments (Nassau/Suffolk towns) require stamped calculations from a NY-licensed Professional Engineer (PE), including tension/uplift calculations for FEMA flood zone compliance.
Professional Engineering Disclaimer: Building codes and municipal permitting requirements are subject to local amendments and periodic updates. The information provided is for general guidance only. Property owners and project managers must consult directly with a licensed Professional Engineer (PE) and the local municipal building department to verify site-specific permitting, soil boring, and inspection requirements before commencing work.

Verified Contractors Servicing New York Coastal & Long Island

Helical Pile Solutions / HPS of NY LLC

✓ Verified Installer
📍 Islip, NY • System: CHANCE® (Hubbell Power Systems)

Preferred installer of AB Chance and Magnum Piering systems. Division of High-Rise Industries operating across Long Island, NYC, and northern NJ....

Pricing Model: Contract / Project quote
View Qualifications → Call (631) 306-4998

Curren Environmental, Inc.

✓ Verified Installer
📍 Cherry Hill, NJ • System: CHANCE® (Hubbell Power Systems)

Certified CHANCE Helical Pier installation contractor. Self-performs structural underpinning and coordinates independent PE structural drawings for mu...

Pricing Model: Turnkey engineering package
View Qualifications → Call (856) 858-9509