Case Studies

A homeowner observed stair-step cracking in brick veneer, interior drywall separation at door frames, and sloping floors throughout the first level of a 1960s ranch-style home. The seller's disclosure indicated "minor settling" but the buyer's agent requested an independent structural engineering assessment.

AO Engineers conducted an on-site structural inspection including visual observation of all accessible structural components, crack mapping of the foundation and exterior masonry, floor elevation survey using a digital level, and review of available property records. Photographs were taken throughout.

Differential foundation settlement of approximately 2.5 inches at the northeast corner of the structure was identified. Crack mapping and elevation survey data indicated active movement consistent with expansive clay soil conditions beneath the exterior continuous footing. The interior framing showed evidence of distortion consistent with the observed foundation movement.

AO Engineers recommended helical pier underpinning at the northeast foundation corner to arrest movement and provide long-term stability, followed by repair of the affected masonry veneer and interior finishes. A geotechnical investigation was recommended to confirm subsurface conditions. A written structural engineering report was issued documenting the settlement, identifying probable causes, and providing repair recommendations. The report was used to successfully negotiate a repair credit during the real estate transaction, allowing the sale to proceed.

A commercial property owner contacted AO Engineers following a severe wind event that caused visible displacement of roof framing at a 15,000 square foot retail strip center. The insurance carrier requested an independent structural engineering assessment to evaluate the damage.

AO Engineers performed a forensic structural investigation including roof access inspection, review of original construction documents, wind speed data review for the event, and engineering analysis of the as-built roof-to-wall connection details. Photographic documentation was comprehensive.

Multiple roof-to-wall connections had failed due to inadequate hurricane strap installation during original construction. Wind uplift forces during the storm exceeded the capacity of the as-built connections, resulting in partial roof displacement at the building's north elevation. Some pre-existing deterioration of wood blocking at the connections was also noted.

Immediate temporary bracing of displaced roof framing, followed by permanent repair of all affected connections using code-compliant hurricane straps and blocking. A comprehensive review of all roof-to-wall connections throughout the building was recommended. AO Engineers prepared a forensic engineering report distinguishing storm-caused damage from pre-existing construction deficiencies. The report supported the property owner's insurance claim and provided the engineering basis for the repair scope.

A buyer under contract for a 1920s-era Victorian home requested a structural engineering inspection after a home inspector noted concerns about the basement masonry walls and visible deflection in a first-floor beam. The buyer needed an engineering opinion before proceeding.

AO Engineers performed a thorough structural inspection of the residence, including basement masonry wall evaluation, first-floor framing inspection, foundation crack documentation, and review of the attic framing. Floor deflection measurements were taken at the area of concern.

A first-floor carrying beam had been notched by a subsequent plumber, reducing its effective depth by approximately 40% at a critical mid-span location. The reduced section was overstressed under normal residential loading. The original stone foundation walls showed evidence of hydrostatic pressure damage and mortar deterioration, with horizontal cracking indicating some lateral movement.

Immediate sister beam installation alongside the notched member to restore structural capacity, and a comprehensive basement wall waterproofing and drainage system to address hydrostatic pressure. Repointing of deteriorated mortar joints was also recommended. AO Engineers provided a written report identifying the structural deficiencies and recommending corrective measures. The buyer used the report to negotiate a purchase price reduction and required repairs as a condition of sale.

A commercial real estate investment firm required a Property Condition Assessment for a 1975-era, 45,000 square foot office building as part of their acquisition due diligence. The lender required an ASTM E2018-compliant PCA prior to loan approval.

AO Engineers conducted a comprehensive walk-through survey of the building's structural systems, roofing, exterior walls, mechanical systems, electrical systems, and plumbing. Available construction documents were reviewed. Cost estimates were developed for immediate repairs, near-term capital needs, and 10-year capital requirements.

The structural frame was in generally satisfactory condition for its age. Notable findings included deterioration of the built-up roofing membrane requiring near-term replacement, spalling of the concrete parking structure requiring immediate repair, and aging HVAC equipment approaching end of service life.

Immediate concrete repair at the parking structure to prevent further deterioration, budgeted roof replacement within three years, and HVAC replacement planning over the five-year horizon. Estimated immediate repair costs of approximately $85,000 and capital needs of approximately $420,000 over 10 years were documented. The PCA report was accepted by the lender, and the acquisition was completed. The buyer used the cost estimates to negotiate a purchase price adjustment and establish an appropriate capital reserve.

A homeowner's concrete block retaining wall, approximately 6 feet high and 80 feet long, partially collapsed following a period of heavy rainfall. The homeowner's insurance carrier disputed coverage, claiming the collapse resulted from a design deficiency rather than a storm event.

AO Engineers performed a forensic investigation including on-site inspection of the failed wall, review of available construction information, soil sampling, review of precipitation records, and engineering analysis of the wall's original design capacity versus actual loading conditions.

The retaining wall lacked adequate drainage provisions — no weep holes or drainage aggregate were present behind the wall. Hydrostatic pressure from saturated soil following the heavy rainfall significantly exceeded the wall's design capacity. The wall's original construction was deficient by current and period-of-construction standards.

Replacement wall design incorporating adequate drainage provisions, including drainage aggregate backfill, filter fabric, and weep holes at regular spacing. The replacement wall was designed with an appropriate factor of safety for the site conditions. AO Engineers' forensic report established that the wall failure resulted from a combination of original construction deficiencies and the rainfall event. The report supported the homeowner's claim and the matter was resolved through mediation.

The owner of a four-story 1890s-era commercial masonry building in a historic district required a structural assessment to support a planned renovation and adaptive reuse project. The building had been vacant for several years and showed visible signs of deterioration.

AO Engineers conducted a comprehensive structural assessment of the building, including evaluation of the exterior masonry walls, interior timber framing, floor systems, and roof structure. Probe openings were made in several locations to observe concealed framing conditions. A written assessment report with photographic documentation was prepared.

The exterior masonry walls were structurally sound with isolated areas of mortar deterioration requiring repointing. The interior timber floor framing was in generally satisfactory condition, with localized deterioration at several locations where roof leaks had caused wood rot. The roof structure required significant repair and partial replacement.

Repointing of deteriorated masonry joints, repair of deteriorated floor framing members, and a comprehensive roof structure repair and replacement program. Recommendations for structural reinforcement to support the proposed renovation loads were also provided. The assessment report provided the building owner and their architect with a clear understanding of existing structural conditions and the engineering requirements for the renovation project. The project proceeded to design and was successfully completed.

A homeowner wished to remove a first-floor interior wall to create an open floor plan connecting the kitchen and living room. A contractor had advised that the wall appeared to be load-bearing, and the homeowner required engineering confirmation and a structural design for a replacement beam.

AO Engineers inspected the residence, evaluated the framing above the proposed wall removal location, traced the load path from the roof through the floor structure, and confirmed that the wall was load-bearing. Engineering calculations were performed to size a replacement beam and posts.

The wall was confirmed to be load-bearing, carrying floor and roof loads from above. The existing foundation was adequate to support the new concentrated post loads. A LVL beam of appropriate size was designed to span the opening, with posts at each end bearing on new footings.

Installation of a specified LVL beam with appropriate bearing length at each end, steel post columns at each bearing point, and new concrete footings beneath each post. Stamped structural drawings were provided for the building permit application. The homeowner obtained a building permit using AO Engineers' stamped drawings. The project was completed successfully, achieving the desired open floor plan.

A logistics company leasing a warehouse facility planned to install new high-density racking systems with significantly greater floor loads than the original warehouse design. The building owner required a structural engineering evaluation before approving the tenant's installation.

AO Engineers reviewed the original structural drawings, conducted an on-site inspection of the concrete floor slab and structural frame, obtained the racking system specifications and proposed layout from the tenant, and performed structural analysis of the floor slab under the proposed racking loads.

The existing concrete floor slab was adequate for the proposed racking loads in most areas of the warehouse. However, at two locations where the racking layout placed concentrated leg loads near existing construction joints, the slab lacked adequate capacity without reinforcement.

Slab reinforcement at the two identified locations using steel plates and epoxy anchors to distribute the concentrated leg loads. The reinforcement details were designed to be installed without disrupting the floor surface. AO Engineers provided a written structural evaluation report and reinforcement design drawings. The tenant installed the reinforcement as designed, and the racking system was approved for installation.

An attorney representing a commercial property owner engaged AO Engineers as a structural engineering expert in a construction defect case involving alleged deficiencies in the structural framing of a newly constructed commercial building. The case was in preparation for trial.

AO Engineers reviewed the construction documents, shop drawings, inspection records, and prior expert reports. A site inspection was conducted with photographic documentation. Engineering analysis was performed to evaluate the alleged deficiencies against applicable code requirements and industry standards. A written expert report was prepared in compliance with applicable procedural rules.

Engineering analysis confirmed that several steel beam connections were fabricated and installed with weld sizes below the minimum required by the structural drawings and AISC standards. The deficient connections reduced the structural capacity of the affected beams below the required design capacity.

Repair of the deficient connections by a qualified structural steel contractor in accordance with a repair design prepared by a licensed structural engineer. Cost estimates for the repair work were provided. AO Engineers provided deposition testimony and was prepared to testify at trial. The case settled prior to trial, with the contractor agreeing to fund the required repairs.

A property management company overseeing a 48-unit apartment complex from the 1970s commissioned a structural assessment to evaluate the condition of the building's structural systems and support capital planning for the coming five-year period.

AO Engineers conducted a systematic structural assessment of all accessible structural components throughout the complex, including foundation walls, framing, balconies, stairways, and parking areas. Each building in the complex was inspected, and findings were documented with photographs and descriptions.

The structural framing was in generally satisfactory condition. Primary concerns included deteriorated balcony framing at several units requiring near-term replacement, cracking in the parking lot slab requiring repair to prevent water infiltration, and isolated foundation crack monitoring recommended at two locations.

Prioritized repair recommendations were provided including immediate balcony repairs at four units with active wood deterioration, near-term balcony assessment and repair at all remaining units, parking lot crack repair, and annual monitoring of the noted foundation cracks. AO Engineers delivered a comprehensive assessment report with a prioritized repair schedule and cost estimates. The property management company used the report to develop their five-year capital plan and communicate repair needs to the property owner.