A 140-page engineering report confirms that ongoing ground movement beneath an Orlando apartment complex forced to evacuate over 350 residents stems from deep-seated sinkhole conditions affecting the entire building, with no reliable solution yet identified.
The Structural Crisis Revealed
Simpson Gumpertz & Heger, engineers hired by property owner Northland, found that portions of the Rialto Apartments on Sand Lake Road have moved downward by approximately 2 inches on average since 2016. The most heavily damaged sections show even greater displacement. Investigators discovered downward movement across the entire building footprint, supported by voids beneath concrete slabs, uneven elevations, and satellite monitoring data. The report concludes the movement results from soil shifting into voids in underlying limestone, conditions typical of karst terrain or sinkhole activity.
The investigation found no evidence that plumbing, drainage, fire protection systems, or other building utilities caused the structural problems. Engineers identified a roughly 15-foot-wide, 3-foot-deep void beneath two apartment stacks that produced some of the most severe damage. However, smaller voids exist throughout the building. The most extensive visible damage remains concentrated around Units 145 and 147, where emergency stabilization work was completed but proved insufficient to make the property habitable.
Legal Thresholds And Repair Challenges
The building currently meets two criteria under Florida law used to define structural damage involving excessive floor and foundation movement. Engineers recommend filling voids beneath the entire building to restore support to the concrete slab, but they caution that grouting alone would not stop the broader downward movement. Additional stabilization options include more extensive grouting or deep foundation systems. The site presents a significant engineering challenge because competent rock lies more than 200 feet below ground level, making traditional foundation solutions difficult and expensive.
What Happens Next
Engineers will determine whether a reliable long-term mitigation solution is feasible. If possible, options for the most heavily damaged sections could include localized repairs, lifting and releveling portions of the structure, or removing and reconstructing affected areas. The Rialto has remained empty since the March evacuation when residents reported loud popping sounds, cracking, and doors that would not open. Orange County’s Division of Building Safety received the report on September 17 and will continue monitoring the property until the owner decides how to proceed. Because the building remains unoccupied, the county states there is no immediate risk to life safety.