TRC provided structural restoration services for Horizon House, a twelve-story Gulf-front condominium originally constructed circa 1970. The cast-in-place concrete structure consists of two-way flat plate slabs supported by reinforced concrete columns, with six residential units per floor.

The building exhibited deterioration at column bases within elevated planter areas. Long-term irrigation and rain saturation — compounded by failed planter linings and invasive root growth — allowed moisture intrusion into adjacent concrete. High concrete permeability, carbonation, reinforcing congestion, and poor consolidation led to reinforcing steel corrosion and spalling at the column faces. Additional leakage was traced to embedded electrical conduit and deteriorated cast iron drain piping.

TRC’s restoration program began with complete removal of planter materials and mechanical surface preparation. Deteriorated concrete was removed to sound aggregate, exposed reinforcing was abrasive-cleaned and treated with an epoxy-cement corrosion protection system, and column bases were rebuilt using flowable micro-concrete. Repairs were extended to achieve proper cover in accordance with ACI requirements.

The rehabilitated planter assemblies were waterproofed using a cold-applied modified polyurethane membrane over a sealed cant condition, followed by 24-hour flood testing to verify watertight performance. Planter systems were then protected with HDPE root barriers and drainage composite. Obsolete embedded drain piping was replaced with external PVC risers and laterals with sealed penetrations, and lighting systems were upgraded with new weather-resistant fixtures and conduit.

The completed restoration mitigated moisture intrusion, addressed active corrosion, and extended the service life of this coastal residential structure.