Reinstallation In Situ on Lime Mortars of a Mosaic Previously Re-Laid on Concrete

This training, held in Volubilis Morocco in 2018, provided mosaic technicians with experience in addressing the increasingly common conservation problem of re-laid mosaics on archaeological sites.
In the past, mosaics excavated on archaeological sites were normally conserved for the future by detaching them from their original lime mortar foundations and relaying them on a new bedding using concrete-- a much stronger, more resistant material.
Decades later, many mosaics detached and relayed on sites are in very poor condition due either to the corrosion and expansion of the concrete reinforcement elements or to fractures resulting from ground movement below the rigid panel and environmental exposure above.
While structural treatments can repair the damage to these mosaic panels, the long-term solution to their conservation is to remove the concrete backing and relay the mosaic back on a bedding of layers of lime mortar similar to the original foundation.