Historic Plaster Ceiling Restoration

This historic building at 417 South Hill Street in Downtown Los Angeles—formerly the iconic Subway Terminal—required extensive restoration of its decorative plaster coffer ceiling. Years of neglect and water exposure had caused severe damage, with multiple sections collapsing and creating numerous holes throughout the ornate ceiling structure.

The original decorative plasterwork represented a significant piece of Los Angeles architectural history that needed to be preserved while being made structurally sound for continued use.

The Challenge

Water damage is one of the most destructive forces for historic plaster. Prolonged exposure had weakened the plaster bond, caused sections to separate from the lath, and left residual contamination that could prevent new materials from adhering properly.

• Multiple areas of complete plaster collapse
• Extensive holes across the ceiling structure
• Decorative coffer details requiring reproduction
• Water contamination affecting material bonding

Our Approach

The restoration required a methodical approach to ensure both structural integrity and historical accuracy:

1. Surface Preparation: Applied primer coating to block residual water contamination that could prevent patching compound from bonding properly.
2. Structural Repair: Removed larger damaged plaster sections completely before replastering to ensure a solid foundation.
3. Patching: Carefully patched smaller affected areas while maintaining the original profile and texture.
4. Historic Reproduction: Molded, fabricated, and installed ceiling and column elements to reproduce the original historic decorative details.

The Result

The completed restoration returned the ceiling to its original grandeur while ensuring long-term durability. The decorative coffer patterns and column details were faithfully reproduced, preserving this piece of Downtown LA's architectural heritage for future generations.