A Multi-Step Approach to Damage Surveying – Part 1 of 2

Spalling concrete beam encasement

A few years ago, a client called CBI with a business emergency: multiple ISD citations required the client to vacate the facility that it was leasing.  Violations included electrical hookup problems, exposed abandoned elevator shafts, failure to change occupancy, failed sprinkler heads, broken windows, and structural damage to stairways and floor framing.  The client wanted CBI to perform a visual review of structural conditions because the extent of the damage was the least defined item of all the causes of the violations.

The building is a four-story former garage built in the early 20th century.  From our review, we concluded that the construction is concrete-encased steel columns, beams, and joists with structural reinforced concrete floor slabs.  There was extensive delamination of beam encasements, overhead cracking and delamination of structural slabs, falling hazards from damaged terracotta walls at one stairway, and severe corrosion of some steel elements.  The worst steel deterioration was the first floor framing, over the partial basement, where entire sections of concrete encasements had separated and fallen to the slab-on-grade below as water infiltration degraded the steel beams over many years.

Spalling concrete & corroding steel at first floor slabs

The report that CBI prepared prompted additional inspection so we visited the structure along with a contractor.  The goals were a) to perform a thorough survey of structural framing, and b) use the survey information to estimate the construction cost to repair the building to its original condition.  CBI allocated three (3) full days to the survey, and with a contractor’s assistance, we sounded approximately 90% of the horizontal framing.  We itemized all the repair types and applied unit prices.  At the beginning of the project, the client gave us a construction proposal from a local contractor to perform repair work on the building.  CBI’s independent construction cost estimate exceeded the contractor’s by 12.5% – a satisfactory result considering CBI’s broader familiarity with the extent of damage.