Preservation Problems and Carried Out Interventions
Conditions Before the 2003-04 Intervention
The preserved surfaces of this room were treated for the first and last time during the excavations directed by Giacomo Boni (1900-02).
The most visible signs of this intervention, are the dark cement rims along the perimeter of the fragments. These rims, applied to provide stability to the wall plasters, together with the cement used for filling up numerous voids, constitute a strong visual disturbance.
Of note is the fact that the 1900-02 intervention avoided any form pictorial re-integration, such as retouches and re-paintings.
The comparison with the current state with the historical photographs realized more than 100 years ago indicates that, with the exception of the northern wall, the conditions appear to be practically unaltered. A grayish surface deposit is present, composed by a thin gypsum incrustation which includes atmospheric particulate.
Further forms of degradation are present on the paintings of the northern wall, caused by the action of water soluble salts such as efflorescences and white patinae, probably subject in the past also to rainwater infiltrations coming from the large window. The painting layer is usually stable, while the wall plasters present numerous and extensive adhesion problems.
Restoration Operations Carried Out during 2003-04
Consolidation of wall plaster, both painted and not, through hydraulic mortar injections in order to re-establish adhesion between the various layers of plaster and between plaster and brick wall surface (this intervention has been carried out systematically throughout the whole monument during the second phase of the project: 2002-03).
Removal of cement rims and fillings through the use of micro-drills equipped with diamond mills and substitution with lime mortar.
Cleaning of painted surfaces and of the wall plaster belonging to the higher portion through the use of chemical agents capable of dissolving gypsum encrustations and successive scalpel touch-up.
Sample cleaning of the velum of the western wall. The removal of the grayish deposit, composed by a thin gypsum encrustation which fixes the atmospheric particulate, enables a notable recovery of the painting’s chromatic values.
A non-cleaned area documents the effect of the removal of the grayish deposit inside the southern wall niche.