Restoring the CNN Center after tornado damage
A landmark tower with three different exterior materials, restored around other trades while repairs were still underway.
The CNN Center in downtown Atlanta is the world headquarters of the Cable News Network, holding its newsrooms and studios alongside commercial office space. The building is built from precast stone, architectural glass and stainless steel, which is an unusual combination and the reason this job needed three separate chemistries rather than one.
What brought us there
A tornado hit downtown Atlanta in 2008 and damaged the building. Presto had already worked on the facade over a number of years, and came back as part of the repair effort, working alongside several construction companies while they completed their own work on the structure.
That is the constraint worth noting. This was not an empty building with a clear schedule. The restoration had to fit around other trades on an occupied landmark in the middle of a city.
What needed doing
Damaged caulking across the joints, waterproofing that needed bringing back, and years of weathering on all three materials: staining on the precast, surface damage and light scratching on the glass, and corrosion on the stainless steel.
Stainless steel is its own problem
Stainless resists corrosion, it does not escape it. Mineral deposits, rust, salts and efflorescence all mark it, and the usual response of scrubbing harder leaves the surface duller than it started. It needs a product that lifts the deposits off rather than abrading them away.
What was used
The architectural glass was restored with Glass ReSurfacer Final Polish, worked with a Glass ReSurfacer Pad, which clears staining, surface damage and light scratching. Glass Defender followed as the protective coating.
The stainless steel was brought back with EnviRestore Metal Stain Remover, which takes off mineral deposits, rust, salts and efflorescence, then sealed with Metal Protector MD to slow the return of corrosion.
The precast stone was cleaned with Stone Restore HD, an acid-based cleaner that handles mineral staining and efflorescence. Damaged caulking was replaced with silicone sealant, and a waterproof coating went onto the precast of the north tower.
Getting to it
Access was by swing stage and rappelling equipment, which is what a tower of this height and shape requires to reach every elevation.
Products used on this project
- Glass ReSurfacer Final Polish — glass restoration
- Glass ReSurfacer Pad 6″ — the polishing pad
- Glass Defender — glass protection
- EnviRestore Metal Stain Remover — stainless steel
- Metal Protector MD — metal protection
- Stone Restore HD — cleaning the precast stone