Addressing Severe Roof and Structural Deterioration in an Aggressive Process Environment
Technical Assurance performed a comprehensive roof and structural assessment at an active pulp and packaging manufacturing facility. The evaluated building dates to 1939 and 1946 and houses bleach operations that create an aggressive chemical environment. Over time, this exposure contributed to deterioration of both the roof assembly and its supporting structural systems.
The assessment evaluated the existing roof system, deck, and structural framing. Technical Assurance also performed structural analysis using applicable existing building code requirements and referenced ASCE loading standards. FM Global snow load requirements were evaluated as part of the analysis.
Evaluating Deterioration Beyond the Roof Surface
The investigation found roof systems in very poor to failed condition, along with saturated and deteriorated insulation and wood decking. Concrete roof slabs exhibited cracking and spalling, with reinforcing steel exposed in some areas.
Structural steel framing also showed significant corrosion, particularly around penetrations and low-slope areas. Approximately 100 deteriorated roof penetrations added to the complexity of the existing conditions. Testing also identified lead-containing coatings on structural steel, requiring additional consideration during planning.
Connecting Roof Conditions With Structural Performance
The assessment went beyond documenting visible deterioration. Structural analysis determined that portions of the existing framing were overstressed by more than 20 percent under FM Global snow load criteria.
Based on the extent of deterioration and associated operational risk, Technical Assurance recommended full roof replacement, partial deck replacement, and targeted structural reinforcement. Two strategies were developed to address the structural requirements: replacing the existing concrete deck with a lighter steel deck or reinforcing the existing framing with supplemental steel members.
Developing a Solution for an Operating Industrial Facility
The preferred approach replaces portions of the existing concrete deck with lighter steel deck. This reduces dead load on the existing framing while improving structural resilience and reducing long-term risk.
Technical Assurance also developed drainage improvements, overflow provisions, structural reinforcement sequencing, and construction coordination protocols. These measures support implementation within the active manufacturing environment while addressing the interconnected roofing, structural, and operational conditions identified during the assessment.
By evaluating the roof and supporting structure as interconnected systems, Technical Assurance provided the client with a coordinated path forward. The resulting strategy addresses immediate deterioration while supporting safer implementation and long-term facility performance.
