Hayden Planetarium Mosaic

When the Hayden Planetarium in the American Museum of Natural History was being demolished, EverGreene was contracted to coordinate the removal and storage of the Aztec Astrological Calendar mosaic set in the terrazzo floor. The mosaic measured at 12 feet in diameter. It was determined that the only way to keep the mosaic intact was to cut out a 16‐ton, 20‐inch‐deep section of the floor, including structural I‐Beams. Riggers with Morse‐Diesel, the general contractor, lifted the mosaic to the ground floor where it was removed through a demolished wall and then hoisted onto a wide‐load truck for transportation.

EverGreene developed technical and engineering solutions for welders and riggers involved in the removal and reinstallation of the mosaic floor in the Rose Center for Earth and Space. In order for our technicians to remove the excess flooring material from the back of the mosaic, we contracted with Urban D.C. to design and engineer a dual‐cradling system. The cradle provided the integral support necessary to flip the mosaic back without stressing it. This steel armature served as the permanent support system for the mosaic in its new location.

We consolidated voids in mortar bed, performed surface cleaning of the grout and mosaic, reattached loose tesserae, replaced missing tesserae to match the original, and regrouted.