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Corrosion Compromising Integrity of Floor Structure

Corrosion Compromising Integrity of Structural Steel Supporting Floor
Corrosion Compromising Integrity of Structural Steel Supporting Floor
Corrosion and slime on floor beams in a crawlspace
Corrosion and slime on floor beams in a crawlspace

Location

Crawlspace beneath a grocery store.

Material

Wide flange steel beams, steel decking, and concrete floor.

Background

A corrosion investigation was performed in a 100,000 square-foot crawlspace built over what was once a low-lying marsh and landfill site. The wide flange steel beams supporting the concrete floor had severely corroded, reducing their service life assessment to only an additional two to five years. Additionally, severe deterioration to the underside of the floor was detected, requiring immediate repair.

Service Life

The grocery store was built 15 years prior to the corrosion inspection.

Findings

The corrosion inspection concluded that there was virtually no air movement in the crawlspace area. The lack of air movement combined with the extremely wet environment of the crawlspace had resulted in this severe corrosive environment. Recommendations were provided for the repair of the concrete and to increase airflow and reduce moisture in the crawlspace to mitigate the corrosion problem and increase the life expectancy of the floor structure.