CORROSIONMAPPING
CORROSION MAPPING
Historic Alameda Bank Building — Saltwater Corrosion Threatens 1910 Structure
The Problem
A historic bank building in Alameda, California was experiencing severe corrosion and concrete failure in its basement. The cause: high water fluctuation from tidal flow and the building’s close proximity to the bay. Briny water was accelerating the corrosion rate of both the embedded steel and the concrete itself — raising serious concerns about the structural integrity of the entire building.
Built in 1910, the structure had been constructed without any corrosion protection for its embedded rebar and structural steel. A century later, the damage was catching up to it.
The Diagnosis
Foundation Tech was originally contracted to perform repairs based on visual inspections and prior geology reports. Instead of doing cursory patchwork, we recommended a thorough damage investigation to understand the full scope of the problem before committing to any repair strategy.
The investigation included:
- Nondestructive corrosion mapping and predictability inspections
- Chloride testing
- Concrete compression strength tests
- Ground penetrating radar to map embedded rebar, structural steel, and any voids beneath floors and perimeter walls
- Visual inspection of columns and footings — which, due to high water levels, required exposing footing pads at the basement level as recommended by the attending structural engineer
- Four core samples taken at locations identified by excessive rust and efflorescence staining, sent to testing laboratories for chloride analysis, moisture content, hardness, and composition.
ICOR corrosion mapping was performed on all basement walls, columns, and beams.
The Approach
All inspection and testing was conducted over the course of a week, entirely after hours — allowing the bank to continue normal operations throughout the investigation.
The Goal
Three key outcomes drove the entire investigation:
- Determine the true structural integrity of every load-bearing element in the building
- Identify all probable water intrusion channels
- Develop a comprehensive long-term rehabilitation and maintenance plan
The Outcome
The detailed inspection and data analysis revealed that the corrosion and damage were significantly more extensive than originally expected.
- Water had corroded the column I-beams in every below-grade footing
- The perimeter walls were in serious need of rehabilitation
- Core samples showed the concrete strength was well below optimal in multiple perimeter wall sections
- GPR scanning revealed multiple voids beneath the structure — any of which could have resulted in collapse
Within 60 days of receiving the laboratory test results, Foundation Tech delivered a detailed emergency repair plan combined with a multi-step rehabilitation proposal — fully engineered and coordinated with the historical architectural committee to satisfy the city’s permit requirements.
Emergency repairs were completed in the fall of 2020, with phased rehabilitation beginning in 2021.
Through thorough investigation and engineered solutions, Foundation Tech helped divert what could have been a catastrophic loss to an important historical structure — and preserved a piece of Alameda’s architectural heritage for the next century.
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The Repair You Need Today Will Cost Less Than the Emergency You’ll Face Tomorrow.
Foundation Tech’s sales engineers are ready to evaluate your foundation or concrete issue, identify the most effective repair method, and deliver a comprehensive proposal with scope, timeline, and pricing.
Don’t wait for a small problem to become a shutdown.
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