Independent forensic investigation of structural steel corrosion — section loss, capacity reduction, and structural significance assessment.
Steel corrosion forensic investigation assesses the extent of section loss, evaluates remaining structural capacity, determines causation, and recommends remediation. PE-stamped reports support maintenance planning, insurance claims, and litigation for commercial and industrial structures.
Atmospheric Exposure
Oxygen and moisture in the atmosphere cause progressive oxidation — accelerated in coastal, industrial, or high-humidity environments.
Chloride Exposure
Deicing salts, marine environments, and chloride-containing atmospheres break down protective oxide films, accelerating corrosion attack.
Carbonation
In concrete-encased steel, carbonation reduces concrete alkalinity, destroying the passive protective film and initiating corrosion.
Galvanic Coupling
Contact between dissimilar metals in the presence of an electrolyte causes accelerated corrosion of the more anodic metal.
Chemical Attack
Exposure to acids, alkalis, or industrial chemicals directly attacks steel, causing rapid section loss in affected areas.
Coating Failure
Deteriorated or damaged protective coatings expose bare steel to the environment, initiating localized corrosion that can spread.
Pack Rust
Corrosion between faying surfaces (bolted connections) produces expansive forces that can distort connections and fracture bolts.
Visual survey of all accessible structural steel, documenting corrosion location, extent, and severity.
Section loss measurement — using calipers, ultrasonic thickness gauges, and dimensional comparison to original specifications.
Coating assessment — evaluating paint condition, coating adhesion, and areas of breakdown.
Connection inspection — evaluating bolted and welded connections for pack rust, bolt fracture, and weld cracking.
Structural analysis — calculating remaining capacity based on measured section loss and original design loads.
Environmental assessment — evaluating exposure conditions, moisture sources, and chemical contaminants.
Material testing — chemical analysis of corrosion products and steel chemistry when galvanic or chemical attack is suspected.
PE-stamped report with extent, significance, causation, and remediation recommendations.
Section Loss
Measurable reduction in flange, web, or member thickness — quantified by ultrasonic testing or dimensional comparison to design drawings.
Flaking & Pitting
Surface corrosion products, pitting patterns, and pack rust at connections indicate the type and severity of corrosion attack.
Coating Breakdown
Blistering, peeling, or discolored protective coatings reveal where steel is exposed and corrosion is active.
Connection Distortion
Pack rust between faying surfaces causes visible distortion of connection plates and can fracture bolts — a structural concern.
Environmental Conditions
Moisture sources, chloride exposure, chemical contact, and humidity levels explain why corrosion is occurring at specific locations.
✗ Surface rust on steel is always a structural concern.
✓ Light surface rust without significant section loss is often cosmetic. Engineering investigation with section loss measurement determines whether capacity is affected.
✗ Painting over rust solves the problem.
✓ Painting over active corrosion without proper surface preparation and treatment only slows deterioration temporarily. The corrosion process continues beneath the coating.
✗ Steel corrosion is always slow and predictable.
✓ Corrosion rates vary dramatically with environment — chloride exposure or chemical attack can cause rapid section loss. Investigation determines actual rates and remaining service life.
PE-stamped forensic report with corrosion extent and significance
Section loss measurements and remaining capacity calculations
Connection inspection findings
Coating condition assessment
Environmental evaluation and corrosion rate assessment
Remediation recommendations — cleaning, coating, reinforcement, or replacement
Prioritized repair scope with cost considerations
Steel corrosion in commercial and industrial structures affects safety, serviceability, and asset value. For property owners and facility managers, an independent engineering investigation provides the data needed for maintenance planning, capital budgeting, and insurance documentation. Unaddressed corrosion progresses, increasing repair costs and potential liability.
Steel corrosion cases involve claims against designers (inadequate corrosion protection), contractors (poor coating application), and owners (maintenance neglect). Key considerations: determining whether corrosion resulted from design deficiency, construction defect, or maintenance failure. Section loss measurement and capacity analysis provide the evidence for responsibility allocation.
Steel corrosion is typically excluded as gradual deterioration and wear. However, if corrosion results from a covered event (storm damage to coating, chemical spill, water intrusion), partial coverage may apply. Our PE-stamped reports differentiate covered causation from excluded gradual deterioration.
Independent engineering answers about steel corrosion
Using ultrasonic thickness gauges, calipers, and dimensional comparison to original design drawings. The measured thickness is compared to design thickness to calculate percentage section loss and remaining structural capacity.
Significance depends on member location, load level, and redundancy. Generally, section loss exceeding 25% of flange or web area warrants structural evaluation. A PE-stamped analysis provides the authoritative assessment.
Yes, depending on extent. Surface cleaning and recoating addresses early corrosion; welded reinforcement plates restore capacity for moderate section loss; full member replacement is required for severe deterioration. An independent engineer determines the appropriate approach.
Discuss your commercial, industrial, insurance, or litigation-related engineering matter with an independent forensic engineer. All consultations are confidential.