Project Type: Evaluation, Design, and Construction Administration
Garage and Balcony Concrete Repairs and Waterproofing
Issue
Vital Structures LLC was initially retained by the owners to perform an evaluation of the existing cast-in-place reinforced concrete framing at the open-air garage. The owner reported that spalled concrete was falling from the first-floor one-way rib slab, and that steel reinforcing was exposed at several locations. Furthermore, the owners reported that the first-floor concrete balconies routinely had ponding water against the building during rain events.
Spalled Concrete at Reinforced Concrete Column
Failed sealant and low flashing height at balcony sliding door
Spalled Concrete One Way Rib Slab
Heavily corroded steel anchor bolt at sill plate
Heavily corroded steel reinforcing at spandrel beam
Corroded steel reinforcing at hole in first floor slab
Concrete balcony with slope towards building
Diagnosis
Upon review, we identified several locations where the existing steel reinforcing was originally placed with limited/insufficient concrete cover. This resulted in accelerated corrosion of the steel reinforcing and subsequent delamination of the concrete. Furthermore, due to the negative slope of the balconies towards the building, we observed that the structural wall wood framing at the base of balcony was rotted with anchor bolts corroded.
Our Solution
Vital Structures was contracted by the owner to provide a design for repairing the deteriorated concrete structure, re-sloping with repairs of the balconies, wood wall framing repairs, and concrete protective coatings. Furthermore, due to local historic commission, the concrete repair design was required not to change the building’s aesthetic. Therefore, custom-colored coatings were furnished by the contractor, and replacement of building components in like kind were a requirement of the design.
Coating installation at underside of the first-floor ribbed slab
Result
Based upon our design, the owner’s hired contractor performed approximately 1700 square feet of overhead concrete repairs, placement of rectangular stub column extensions, section enlargement of existing circular concrete columns, installation of a new reinforced CMU wall, placement of a sloped topping slab at each balcony, foundation improvements, application of breathable concrete coating at the underside of the garage, and application of a balcony coating system. This project was successfully completed ahead of the owner’s deadline, so that the resort could open for the summer season.
