After its discovery in 1964, the preserved portion of the Octagon’s marble floor, covering an area of 250 sq. m., remained exposed, which resulted n it’s suffering major damage. The majority of the slabs and small plaques were shattered, and as a consequence their fragments – even intact small plaques – become detached from their original substratum. Their state of preservation was worsened by ad hoc interventions carried out during three periods (1970, 1975, 1986). These concerned:
1. The re-attachment of fragments of slabs and plaques on their substratum without being joined together.
2. The completion of destroyed parts of slabs with marble fragments of a different type, the completion of destroyed slabs by fragments (or intact ancient slabs) found within the deposit coming from other locations, resulting in the interruption of the color and geometric unity of the floor.
The above were done with the use of a strong cement mortar further contributing to the slabs’ deterioration.
From 1986 - 2003, conservation works were not repeated, which resulted in additional erosion and fragmentation. More specifically: a good number of slabs presented surface erosion, while throughout the area of the paved surface there were concentrations of soluble salts and biological residues. Beyond altering the color of the slabs, these also contributed to the widening of the slabs’ surface fractures.
Τhe restoration of the marble floor
1. Removal of cement mortar from the plaques, and the resetting of detached, intact small marble plaques on a new, compatible mortar substratum.
2. Assembling and gluing of the fragmentary slabs and small plaques, and integration of their destroyed parts with compatible mortar of a similar color/hue.
3. Aesthetic restoration of the floor with the integration of its destroyed sections. More specifically: in place of the destroyed plaques, new ones with similar characteristics were placed, to restore the floor’s design and color synthesis, which is chiefly based on the alternation of white and red marble. The few intervened areas were demarcated by a stainless steel plates border. Larger gaps lacking documentation concerning the type of marble with which they had been paved were completed with compatible mortar.